Film Properties of Plastics and Elastomers – A Guide to Non-Wovens in Packaging Applications

Film Properties of Plastics and Elastomers – A Guide to Non-Wovens in Packaging Applications
Second Edition
Liesl K. Massey
Table of Contents
Introduction
1.0 Packaging Materials . 2
Uses of Packaging Materials 2
2.0 Test Methods . 3
Tests for Physical Properties 3
Tests for Permeability Properties 5
Tests for Optical Properties 6
3.0 Units . 8
4.0 Regulations 8
2.4 Tests for Electrical Properties . 7
The rmop I ast i cs
Acrylic Resin
Acrylonitrile-Methyl-Acrylate Copolymer . AMA . Chapter 1 9
Tabular Information 10
Cellulosic Plastic
Cellulosic . Chapter 2 13
Tabular Information 13
Fluoroplastic
Ethylene Tetrafluoroethylene Copolymer . ETFE . Chapter 3 15
Tabular Information 16
Fluorinated Ethylene Propylene Copolymer . FEP . Chapter 4 17
Tabular Information 18
Perfluoroalkoxy Resin . PFA . Chapter 5 . 21
Tabular Information 22
Polychlorotrifluoroethylene . PCTFE . Chapter 6 25
Tabular Information 26 vi
Polytetrafluoroethylene . PTFE . Chapter 7 . 29
Tabular Information 29
Polyvinyl Fluoride . PVF . Chapter 8 31
Graphical Information 31
Tabular Information 32
Ionomer
lonomer . Chapter 9 . 33
Tabular Information 34
Graphical Information 36
Polyamide
Nylon Overview . Chapter 10 . 41
Tabular Information 42
Amorphous Nylon . Chapter 11 . 43
Tabular Information 44
Nylon 6 . PA 6 . Chapter 12 . 47
Tabular Information 48
Nylon 66 . PA 66 . Chapter 13 . 51
Tabular Information 52
Nylon 6/66 . PA 6/66 . Chapter 14 . 55
Tabular Information 55
Nylon 6/12 . PA 6/12 . Chapter 15 . 57
Tabular Information 58
Nylon 6/69 . PA 6/69 . Chapter 16 . 59
Tabular Information 60
Nylon 661610 . PA 661610 . Chapter 17 . 63
Tabular Information 64
Polyester
Polyethylene Napthalate . PEN . Chapter 18 65
Tabular Information 66
Polycyclohexylenedimethylene
Terephthalate . PCTG . Chapter 19 71
Tabular Information 72 vi i
Po lye t h y I e n e Te re p h t h a I ate
Glycol-Modified . PETG . Chapter 20 . 73
Tabular Information 73
Polyethylene Terephthalate . PET . Chapter 21 . 75
Tabular Information 76
Polyimide
Polyimide . Chapter 22 79
Tabular Information 80
Graphical Information 84
Polyolefin
Polyethylene . Overview . Chapter 23 . 89
Tabular Information 89
Ultra Low Density Polyethylene . ULDPE . Chapter 24 91
Tabular Information 92
Low Density Polyethylene . LDPE . Chapter 25 95
Tabular Information 97
Graphical Information 96
Linear Low Density Polyethylene . LLDPE . Chapter 26 . 99
Tabular Information 100
Metallocene-Catalyzed Linear Low Density Polyethylene . mLLDPE . Chapter 27 103
Tabular Information 104
Graphical Information 105
Linear Medium Density Polyethylene . LMDPE . Chapter 28 . 111
Tabular Information . 112
High Density Polyethylene . HDPE . Chapter 29 . 113
Tabular Information . 114
Polyolefin Plastomers . POP . Chapter 30 . 117
Graphical Information . 117
Tabular Information . 118
Cyclic Olefin Copolymer . COC . Chapter 31 125
Tabular Information 126
Graphical Information 127
Ethylene Vinyl Acetate Copolymer . EVA . Chapter 32 . 129
Tabular Information 131 viii
Ethylene Vinyl Alcohol Copolymer . EVOH . Chapter 33 135
Tabular Information 136
Ethylene Acrylic Acid Copolymer . EAA . Chapter 34 . 139
Tabular Information 140
Biaxially Oriented Polypropylene and Oriented Polypropylene .
BOPP and OPP . Chapter 35 141
Tabular Information 142
Polybutene . PB . Chapter 36 . 145
Graphical Information 146
Tabular Information 147
Vinyl Resin
Polyvinyl Alcohol . PVOH . Chapter 37 149
Tabular Information 150
Polyvinyl Chloride . PVC . Chapter 38 . 153
Tabular Information 153
Polyvinylidene Chloride . PVDC . Chapter 39 . 155
Tabular Information 156
Polyvinylidene Chloride Coated Films .
PVDC Coated Films . Chapter 40 . 159
Tabular Information 162
Mu I ti layer Structures
Multilayer Films
Mylar Films . Ethylene Vinyl Alcohol Barrier . Chapter 41 . 165
Tabular Information 166
Thermoplastic Elastomers
Olefinic Thermoplastic Elastomers
Olefinic Thermoplastic Elastomers . TPO . Chapter 42 167
Tabular Information 168 ix
Polyether Block Amide
Polyether Block Amide . PEBA . Chapter 43 . 169
Tabular Information 170
Polybutadiene Thermoplastic Elastomer . Chapter 44 171
Tabular Information 171
Polyester Thermoplastic Elastomer
Polyester Thermoplastic Elastomer . Chapter 45 173
Tabular Information 174
Styrenic Thermoplastic Elastomer . Chapter 46 . 177
Additional Materials
Metallized Films . Chapter 47 . 179
Tabular Information 179
Biodegradable or Organic Films . Chapter 48 181
Appendix
Glossary of Terms . 183
Indices
Trade Names . 219
References 221 Glossary of Terms
A
ABS: SeeAcrylonitrile Butadiene Styrene Polymer.
ABS Nylon Alloy: See Acrylonitrile Butadiene Styrene
Polymer Nylon Alloy.
ABS PC Alloy: SeeAcrylonitrile Butadiene Styrene Poly-
mer Polycarbonate Alloy.
ABS Resin: See Acrylonitrile Butadiene Styrene Poly-
mer.
Accelerant: SeeAccelerator.
Accelerator: A chemical substance that accelerates
chemical, photochemical, biochemical, etc., reactions or
processes, such as cross-linking or degradation of polymers, that is triggered andor sustained by another substance, such as a curing agent or catalyst, or environmental factor, such as heat, radiation, or a microorganism.
Also called accelerant, promoter, and cocatalyst.
Acetal Resins: Thermoplastics prepared by polymerization of formaldehyde or its trioxane trimer. Acetals have
high impact strength and stiffness, low fiiction coefficient
and permeability, good dimensional stability and dielectric properties, and high fatigue strength and thermal stability. Acetals have poor acid and UV resistance and are
flammable. Processed by injection and blow-molding and
extrusion. Used in mechanical parts such as gears and bearings, automotive components, appliances, and plumbing
and electronic applications. Also called acetals.
Acetals: SeeAcetal Resins.
Acetone: A volatile, colorless, highly flammable liquid
with molecular formula CH,COCH,. Acetone has an
autoignition temperature of 537″C, mixes readily with water and some other solvents, and is moderately toxic. Acetone dissolves most thermoplastics and some thermosets.
Used as organic synthesis intermediate, e.g., in the manufacture of bisphenol A and antioxidants, as solvent in
paints and acetate fiber spinning and for cleaning of electronic parts. Also called dimethyl ketone, 2-propanone.
Acrylate Styrene Acrylonitrile Polymer: Acrylic rubber-modified thermoplastic with high weatherability.
Acrylate Styrene Acrylonitrile Polymer has good heat and
chemical resistance, toughness, rigidity, and antistatic
properties. Processed by extrusion, thermoforming, and
molding. Used in construction, leisure, and automotive
applications such as siding, exterior auto trim, and in outdoor furniture.
Acrylic Resins: Thermoplastic polymers of alkyl acrylates such as methyl methacrylates. Acrylic resins have
good optical clarity, weatherability, surface hardness,
chemical resistance, rigidity, impact strength, and dimensional stability. They have poor solvent resistance, poor
resistance to stress cracking, flexibility, and thermal stability. Processed by casting, extrusion, injection molding,
and thermoforming. Used in transparent parts, auto trim,
household items, light fixtures, and medical devices. Also
called polyacrylates.
Acrylonitrile Butadiene Styrene Polymer: ABS resins
are thermoplastics comprised of a mixture of styrene-acrylonitrile copolymer (SAN) and SAN-grafted butadiene
rubber. They have high impact resistance, toughness, rigidity, and processability,but low dielectric strength, continuous service temperature, and elongation. Outdoor use
requires protective coatings in some cases. Plating grades
provide excellent adhesion to metals. Processed by extrusion, blow-molding, thermoforming, calendaring, and
injection molding. Used in household appliances, tools,
nonfood packaging, business machinery, interior automotive parts, extruded sheet, pipe, and pipe fittings. Also
called ABS, ABS resin, and acrylonitrile butadiene styrene polymer.
Acrylonitrile Butadiene Styrene Polymer Nylon Alloy:
A thermoplastic processed by injection molding, with
properties similar to ABS, but higher elongation at yield.
Also called ABS Nylon Alloy.
Acrylonitrile Butadiene Styrene Polymer Polycarbon-
ate Alloy: A thermoplastic processed by injection molding and extrusion, with properties similar to ABS. Used
in automotive applications. Also called ABS PC alloy.Acrylonitrile Copolymer: A thermoplastic prepared by
copolymerization of acrylonitrile with small amounts of
other unsaturated monomers. Has good gas barrier properties and chemical resistance. Processed by extrusion,
injection molding, and thermoforming. Used in food packaging.
Acrylonitrile Butadiene Styrene Polymer: See Acry-
lonitrile Butadiene Styrene Polymer.
Activation Energy: An excess energy that must be added
to an atomic or molecular system to allow a process to
proceed such as diffusion or chemical reaction.
Adsorption: Retention of a substance molecule on the
surface of a solid or liquid.
Alcohols: A class of hydroxy compounds in which a hydroxy group(s) is attached to a carbon chain or ring. Alcohols are produced synthetically from petroleum stock,
e.g., by hydration of ethylene, or derived from natural
products, e.g., by fermentation of grain. The alcohols are
divided in the following groups: monohydric, dihydric,
trihydric, and polyhydric. Used in organic synthesis, as
solvents, plasticizers, fuels, beverages, and detergents, etc.
AMA: SeeAcrylonitrile Methyl Acrylate.
Amorphous Nylon: Transparent aromatic polyamide thermoplastics. Produced by condensation of hexamethylene
diamine, isophthalic and terephthalic acid.
Annulus Test: An ozone resistance test for rubbers that
involves a flat-ring specimen mounted as a band over a
rack, stretched 0 to loo%, and subjected to ozone attack
in the test chamber. The specimen is evaluated by comparing to a calibrated template to determine the minimum
elongation at which cracking occurred.
Anthraquinone: An aromatic compound comprising two
benzene rings linked by two carbonyl (C=O) groups,
C,H,(CO),C,H,. Combustible. Used as an intermediate in organic synthesis, mainly in the manufacture of
anthraquinone dyes and pigments. One method of preparation is by condensationof 1,4-naphthaquinone with butadiene.
Antioxidant: A chemical substance capable of inhibiting
oxidation or oxidative degradation of another substance
such as plastic in which it is incorporated. Antioxidants
act by terminating chain-propagating free radicals or by
decomposing peroxides, formed during oxidation, into
stable products. The first group of antioxidants include
hindered phenols and amines; the second group includes
sulfur compounds, such as thiols.
Ar: See argon.
Arc Resistance: Arc Resistance is the relative ability of
a material to withstand arcing across its surface when electrodes placed on the specimen are impressed with high
voltage (low amperage) current.
Area Factor: The ratio between the total area of pore
openings on the surface of a membrane that is in contact
with the incoming flow of a penetrant, to the area of this
surface.
Argon (Ar): A chemically inert, tasteless, colorless, noncombustible monoatomic gas. Argon is often used to characterize permeability of polymeric films, such as carrier
gas in gas chromatography, as inert gas shield in welding,
in electric bulbs such as neon, lasers, and as a process
environment.
Aroma Barrier: A plastic film or its component preventing the escape of aromatic volatiles from foodstuffs or
cosmetics seal-packaged in the film.
Aromatic Polyester Estercarbonate: A thermoplastic
block copolymer of an aromatic polyester with polycarbonate. Has higher heat distortion temperature than regular polycarbonate.
Aromatic Polyesters: Engineering thermoplastics prepared by polymerization of aromatic polyol with aromatic dicarboxylic anhydride. They are tough with
somewhat low chemical resistance. Processed by injection
and blow-molding, extrusion, and thermoforming.Drying
is required. Used in automotive housings and trim, electrical wirejacketing, printed circuit boards, and appliance
enclosures.
ASA: SeeAcrylate Styrene Acrylonitrile Polymer.
ASTM International: Formerly known as the American
Society for Testing and Materials.
ASTM D96: (Discontinued Test Method) Standard test
method for determining water vapor transmission of materials suchas paper, plastic film and sheeting, fiberboards,
wood products, etc., that are less than 31 mm in thickness. Two basic methods, the Desiccant Method and the
Water Method are used. The specimens have either one
side wetted or one side exposed to high humidity and
another to low humidity. In the Desiccant Method, the185
specimen is placed airtight on a test dish with a desiccant
that is weighed to determine the gain of weight due to
water vapor transmission. In the Water Method, the
water is placed in the dish that is weighed to determine
the loss of water due to evaporation through the specimen.
ASTM D149: StandardTest Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical
Insulating Materials at Commercial Power Frequencies
may be used to determine dielectric strength of solid insulating materials. The frequency of the tests is generally
at commercial power frequencies of 60 Hz, but the method
is appropriate for any frequency from 25 through 60 Hz.
Various temperatures and any suitable gaseous or liquid
medium may be used. D149 is used for determining the
dielectric breakdown voltage most often through the thickness of a test specimen (puncture), but also along the interface between a solid specimen and a gaseous or liquid
surrounding medium (flashover). Proof testing may be
performed through the use of Section 12 modifications
instruction.
ASTM D150: Standard Test Methods for AC Loss Characteristics and Permittivity (Dielectric Constant) of Solid
Electrical Insulation includes the determination of relative* permittivity, dissipation factor, loss index, power
factor, phase angle, and loss angle through specimens of
solid electrical insulating materials when the standards
used are lumped impedances. The frequency range that
can be covered extends from less than 1 Hz to several
hundred megahertz.
*In common usage, the word relative is frequently
dropped.
ASTM D256: Standard Test Methods for Determining
the Izod Pendulum Impact Resistance of Plastics. Used
to determine the resistance of a plastic specimen to impact by a pendulum-type hammer. Specimens contain a
milled notch and depending upon the test method, failure
may be brittle or ductile. Testresults are reported in terms
of energy absorbed per unit of specimen width or per unit
of cross-sectional area under the notch.
ASTM D257: Standard Test Methods for DC Resistance
or Conductance of Insulating Materials. Used to determine DC insulation resistance, volume resistance, volume
resistivity, surface resistance, and surface resistivity of
electrical insulating materials, or the corresponding conductances and conductivitiesof insulating materials. D256
is not suitable for use in measuring the electrical resistivitylconductivity of moderately conductive materials.
ASTM D471: An American Society for Testing of Materials. Standard method for determining the resistance of
nonporous rubber to hydrocarbon oils, fuels, service fluids, and water. The specimens are immersed in fluids for
22-670 hours at -75 to 250″C, followed by measuring of
the changes in mass, volume, tensile strength, elongation,
and hardness for solid specimens and the changes in breaking strength, burst strength, tear strength, and adhesion
for rubber-coated fabrics.
ASTM D495: Standard Test Method for High-Voltage,
Low-Current, Dry Arc Resistance of Solid Electrical Insulation. Recommended as a preliminary screening
method to differentiate among similar materials with
respect to their resistance to the action of a high-voltage, low-current arc close to the surface of insulation,
intending to form a conducting path therein or in causing the material to become conducting due to the localized thermal and chemical decomposition and erosion.
D495 will not, in general, permit conclusions to be drawn
concerning the relative arc resistance ranking of materials that may be subjected to other types of arcs: for example, high voltage at high currents, and low voltage at
low or high currents.
ASTM D523: Standard Test Method for Specular Gloss.
Used to determine the specular gloss ofnonmetallic specimens for glossmeter geometries of 20″, 60″, and 85″.
ASTM D542: StandardTest Method for Index of Refiaction of Transparent Organic Plastics. Used to measure the
index of refiaction of transparent organic plastic materials
throughuse of arefiactometer. D542 requires optically homogeneous specimens of uniform refractive index. This
test method and IS0 489 are technically equivalent.
ASTM D570: Standard Test Method for Water Absorption of Plastics. Used to determine the relative rate of absorption of water by plastics when immersed. D570 is
applicable to the testing of all types of plastics, including
cast, hot-molded, and cold-molded resinous products, and
both homogeneous and laminated plastics in rod and tube
form and in sheets 0.13 mm (0.005 in.) or greater in thickness. IS0 62 is technically equivalent to this test method.
ASTM D638: Standard Test Method for Tensile Properties of Plastics is used to determine the tensile properties
of unreinforced and reinforced plastics under defined conditions of pretreatment, temperature, humidity, and testing machine speed. Specimens are dumbbell-shaped and
can be of any thickness up to 14 mm. However, test
Method D882 is the preferred test method for testing filmsless than 1.O mm. Materials with a thickness greater than
14 mm (0.55 in.) must be reduced by machining. D638
also includes the option of determining Poisson’s ratio at
room temperature. This test method and IS0 527-1 are
technically equivalent.
ASTM D696: Standard Test Method for Coefficient of
Linear Thermal Expansion of Plastics Between
-30°C and 30°C. With a Vitreous Silica Dilatometer. Used
to determine the coefficient of linear thermal expansion
by use of a vitreous silica dilatometer for plastic materials having coefficients of expansion greater than 1 x lo6
1°C. Plastic materials generally have negligible creep or
elastic strain rate or both at the temperatures and stresses
herein imposed.
ASTM D774: StandardTest Method for Bursting Strength
of Paper is used to measure the bursting strength of paper
and paper products whose bursting strength lies between
30kPa and 1400kPa. These products shall be single or
laminated flat sheets not over 0.6 mm (0.025 in.) in thickness. This method is similar to IS0 2758 and TAPPI 403.
ASTM D790: Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and
Electrical Insulating Materials. Used to determine flexural properties of unreinforced and reinforced plastics,
and is generally applicable to both rigid and semirigid
materials. D 790 uses a three-point loading system applied to a simply supported beam, and is valid for those
materials that break or fail in the outer surface of the test
specimen within the 5.0% strain limit of these test methods. It should be noted that these test methods are not
technically equivalent to IS0 178.
ASTM D792: Standard Test Methods for Density and
Specific Gravity (Relative Density) of Plastics by Displacement. Used to determine the specific gravity and
density of solid plastics in forms such as sheets, rods,
tubes, or molded items. It should be noted that this standard is not equivalent to IS0 11 83 method A.
ASTM D882: Standard Test Method for Tensile Properties of Thin Plastic Sheeting. Used to determine tensile
properties of plastics in the form of thin sheeting, including film having a nominal thickness not greater than 0.25
mm (0.010 in.). InD882, specimenextensionmaybemeasuredby grip separation, extension indicators, or displacement of gage marks. This test method is similar to IS0
527-3, but is not considered technically equivalent.
ASTM D1709: Standard Test Methods for Impact Resistance of Plastic Film by the Free-Falling Dart Method.
Provides two methods for the determination of the energy, expressed as weight (mass), that causes plastic film
to fail under the impactof a fiee-falling dart. Specified conditionsinclude height fiom whichthe dart will fallas well as
the weight of the dart. Failure energy is when 50% of the
tested specimens fail with a specific weight of dart. Both
methods, the staircase technique and the alternative technique give equivalent results with respect to the dart impact weight at failure as well as to the precisions with
which they are determined. This method is similar to IS0
7765-1, IS0 7765-1 which has several differences.
ASTM D1746: Standard Test Method for Transparency
of Plastic Sheeting. Used to determine the regular transmittance (Tr) of plastic sheeting. The primary use of
D 1746 is with nominally clear and colorless thin sheeting, but the method is generally applicable to any translucent or transparent material.
ASTM D1922: Standard Test Method for Propagation
Tear Resistance of Plastic Film and Thin Sheetingby Pendulum Method. Used to determine the average force to
propagate tearing after the tear has been started using an
Elmendorf-type tearing tester. Two specimens of a specified length of plastic film or nonrigid sheeting are used,
one rectangular type and one with a constant radius testing length. The latter is the preferred or referee specimen.
Provisions are made in the test method to compensate for
oblique directional tearing, which may be found with some
materials.
ASTM D1938: Standard Test Method for Tear-Propagation Resistance (Trouser Tear) of Plastic Film and Thin
Sheeting by a Single-Tear Method. Used to determine the
force necessary to propagate a tear in plastic film and thin
sheeting (thickness of 1 mm or less) by a single-tear
method. D1938 employs a constant rate of separation of
the grips holding the test specimen and the specimen extension may be measured in this test method by grip separation. The method is not applicable for film or sheeting
material where brittle failures occur during testing.
ASTM D2176: Standard Test Method for Folding Endurance of Paper by the M.I.T. Tester.Used to determine
the folding endurance of paper using the M.1.T.-typefolding apparatus. This test method is the technical equivalent of TAPPI T511.
ASTM D2457: Standard Test Method for Specular Gloss
of Plastic Films and Solid Plastics. Used for the measurement of gloss of opaque and transparent plastic films
and solid plastics. D2475 contains three separate gloss
angles: 60″, recommended for intermediate-gloss films,187
20″, recommended for high-gloss films, and 45″, recommended for intermediate gloss and low-gloss films. Note:
The 60″ and 20″ apparatus and method of measurement
duplicate those in ASTM D523; those for the 45″ procedure are similarly taken from ASTM C346.
ASTM D2863: Standard Test Method for Measuring
the Minimum Oxygen Concentration to Support
Candle-Like Combustion of Plastics (Oxygen Index). Used to measure the minimum concentration
of oxygen that willjust support flaming combustion in a
flowing mixture of oxygenandnitrogen. Methods are provided for testing materials that are structurally self-supporting in the form of vertical bars or sheet up to 10.5
mm thick as well as flexible sheet or film materials supported vertically.
ASTM D3420: Standard Test Method for Pendulum Impact Resistance of Plastic Film. Used to determine the
resistance of film to impact-puncture penetration at ambient conditions. Also called Spencer Impact.
ASTM D3985: Standard test method for determining the
steady-state transmission rate of oxygen gas through a
plastic film, sheeting, laminates, coextrusions, or plasticcoated paper or fabric. An American Society for Testing
of Materials.
ASTM D5214: Withdrawn Standard Test Method for
Polyimide Resin Film for Electrical Insulation and Dielectric Application (Withdrawn 1995). Replaced by
D2305: StandardTest Methods for Polymeric Films Used
for Electrical Insulation
ASTM E96: Standard test method for determining water
vapor transmission of materials such as paper, plastic film
and sheeting, fiberboards, wood products, etc., that are
less than 3 1mm in thickness. Two basic methods, the Desiccant Method and the Water Method, are used. The specimens have either one side wetted or one side exposed to
high humidity and another to low humidity. In the Desiccant Method, the specimen is placed airtight on a test dish
with a desiccant that is weighed to determine the gain of
weight due to water vapor transmission. In the Water
Method, the water is placed in the dish that is weighed to
determine the loss of water due to evaporation through
the specimen.
ASTM E398: Standard test method for the determination of water vapor transmission rate of sheet materials
with at least one side being hydrophobic, such as plastic
film, by a rapid dynamic method. The specimen is mounted
between two chambers, one of known relative humidity
and another of dry air. The response of an electrical sensor capable of detecting water vapor accumulation in the
dry chamber is recorded and used, with the help of a calibrating curve, to determine the water vapor transmission
rate. Also called ASTM E398-70.
ASTM E398-70: SeeASTME398.
ASTM E424: Standard Test Method for Solar Energy
Transmittance and Reflectance (Terrestrial) of Sheet Materials. Used to determine solar energy transmittance and
reflectance of materials in sheet form using one of two
procedures. Method A, the referee method, is applicable
for both transmittance and reflectance and uses a spectrophotometer. Method B is applicable only for measurement
of transmittance and uses a pyranometer in an enclosure
and the sun as the energy source. Both test methods have
given essentially equivalent results for those materials
studied by the task group who prepared the method.
ASTM F372: Standard test method for the rapid determination of water vapor transmission rate of flexible barrier films and thin sheeting consisting of single or multilayer synthetic or natural polymers and metal foils including coated materials. The specimen is mounted between
two chambers, one of known relative humidity and another of dry air. The time for a given increase in water
vapor concentration of the dry chamber is measured by
monitoring the differential between two bands in the infrared spectral region, one in which water molecules absorb and the other where they do not. The values obtained
are used to calculate the water vapor transmission rate.
ASTM F1249: Standard test method for determining
water vapor transmission rate through plastic film and
sheeting up to 3 mm in thickness using a pressure-modulated infrared sensor. In addition, this method provides
for the determination of the permeance of the film to
water vapor and the water vapor permeability coefficient.
The specimen is placed as a sealed semi-barrier between
two chambers at ambient atmospheric pressure. One
chamber is wet and another is dry. As water vapor penetrates through the film from the wet chamber into the
dry one it is carried by air into the sensor. It measures
the fraction of infrared energy absorbed by the vapor
and produces an electric signal that is proportionalto water
vapor concentration
ASTM F456: Withdrawn Standard Test Method for Pinhole Flex Life of Films by Axial Vibration of a Tubular
Sample (Withdrawn 1987). No replacement.Atmosphere: A metric unit of measurement of pressure equal to 1.013250 x 1.OE+06 dynes/cm2 or
1.013250 x 1.OE+05pascals, which is the air pressure
measured at mean sea level. It has a dimension of unit of
force per unit of area. Used to denote the pressure of gases,
vapors, and liquids. Also called atm, standard atmosphere,
and std atm.
Azo: A prefix indicating an organic group of two nitrogen atoms linked by a double bond, -N=N-, or a class of
chemical compounds containing this group, like azo dyes.
B
Bar: A metric unit of measure of pressure equal to
1.OE+06 dynes/cm2 or 1.OE+05pascals. It has a dimension of unit of force per unit of area. Used to denote the
pressure of gases, vapors, and liquids.
Barrier Material: Materials such as plastic films, sheeting, wood laminates, particle board, paper, fabrics, etc.,
with low permeability to gases and vapors. Used in construction as water vapor insulation, food packaging, and
protective clothing, etc.
Benzene: An aromatic hydrocarbon with a six-atom carbon ring, C,H,. Highly toxic and flammable (autoignition
point 562°C). A colorless or yellowish liquid under normal conditions (b.p.SO.l”C), soluble inmany organic solvents such as ethanol, acetone, tetrachlorocarbon, etc.
Used for synthesis of organic compounds.
Bisphenol A Polyester: A thermoset unsaturated polyester based on bisphenol A and fumaric acid.
Blowup Ratio: In extrusion blowing of film, it is the
ratio of the extrusion die diameter and the diameter of
the tubular film. In blow-molding, it is the ratio between
the diameter of a parison and the maximum diameter of
the mold cavity.
Blown Film: A plastic film produced by extrusion blowing, wherein an extruded plastic tube is continuously inflated by internal air pressure, cooled, collapsed by rolls,
and wound up. The thickness of the film is controlled by
air pressure and rate of extrusion.
BOPP: Biaxially Oriented Polypropylene.
Bubbling: The presence of bubbles of trapped air andor
volatile vapors in nonmetallic coating or plastic specimen or article. Bubbling is often caused by improper application or excessive mixing of paints or degassing.
Bursting Strength: Bursting strength of a material is
the maximum hydrostatic pressure required to produce
rupture of the material when a controlled and constantly
increasing pressure is applied through a rubber diaphragm
to a circular area.
C
CA: See Cellulose Acetate.
CAB: See Cellulose Acetate Butyrate.
Carbon Black: A black colloidal carbon filler made by
the partial combustion or thermal cracking of natural
gas, oil, or another hydrocarbon. There are several types
of carbon black depending on the starting material and
the method of manufacture. Each type of carbon black
comes in several grades. Carbon black is widely used as a
filler and pigment in rubbers and plastics. It reinforces,
increases the resistance to W light, and reduces static
charging.
Carbon Dioxide: A colorless, tasteless gas, CO,, is found
in the atmosphere. It is produced as a result of metabolism (e.g., oxidationof carbohydrates) and is used by plants
in photosynthesis. Carbon dioxide has low toxicity and is
noncombustible. Derived industrially from synthesis gas
in ammonia production and from cracking of hydrocarbons. Used widely in refrigeration, carbonated beverages,
chemical synthesis, water treatment, medicine, fire extinguishing, and as inert atmosphere.
Carbon Monoxide: A colorless, tasteless gas, CO. Highly
flammable (liquid autoignition point, 609°C) and toxic.
Found in automobile exhaust gases and is a major air pollutant. Manufactured from coke by action of oxygen and
carbon dioxide or steam. Used in organic synthesis, synthetic fuels, and metallurgy.
Cast Film: Film produced by pouring or spreading resin
solution or melt over a suitable temporary substrate,
followed by curing via solvent evaporation or melt cooling and removing the cured film from the substrate.
Cellulose Acetate: Thermoplastic esters of cellulose
with acetic acid. Has good toughness, gloss, clarity,
processability, stiffness, hardness, and dielectric properties, but poor chemical, fire and water resistance and
compressive strength. Processed by injection and blowmolding and extrusion. Used for appliance cases, steering wheels, pens, handles, containers, eyeglass frames,
brushes, and sheeting. Also called CA.Cellulose Acetate Butyrate: Thermoplastic mixed esters of cellulose with acetic and butyric acids. Has good
toughness, gloss, clarity, processability, dimensional stability, weatherability, and dielectric properties, but poor
chemical, fire, and water resistance, and compressive
strength. Processed by injection and blow-molding and
extrusion. Used for appliance cases, steering wheels, pens,
handles, containers, eyeglass frames, brushes, and sheeting. Also called CAB.
Cellulose Propionate: Thermoplastic esters of cellulose
with propionic acid. Has good toughness, gloss, clarity,
processability, dimensional stability, weatherability, and
dielectric properties, but poor chemical, fire and water
resistance and compressive strength. Processed by injection and blow-molding and extrusion. Used for appliance
cases, steering wheels, pens, handles, containers, eyeglass
frames, brushes, and sheeting. Also called CP.
Cellulosic Plastics: Thermoplastic cellulose esters and
ethers. Has good toughness, gloss,clarity, processability,and
dielectric properties, but poor chemical, fire, and water resistance and compressive strength. Processed by injection
and blow-molding and extrusion. Used for appliance cases,
steering wheels, pens, handles, containers, eyeglass
frames, brushes, and sheeting.
Centimeter of Mercury: See cm Hg.
CFR: See Code of Federal Regulations.
Chain Scission: Breaking of the chainlike molecule of a
polymer as a result of chemical, photochemical, etc., reaction such as thermal degradation or photolysis.
Chalking: Formation of a dry, chalk-like, loose powder
on or just beneath the surfaceof paint film or plastic caused
by the exudation of a compounding ingredient such as
pigment, often as a result of ingredient migration to the
surface and surface degradation.
Channel Black: Carbon black made by impingement of
a natural gas flame against a metal plate or channel iron,
from which a deposit is scraped. Used as a reinforcing
filler in rubbers. Also called Gas Black.
Chemical Saturation: Absence of double or triple
bonds in a chain organic molecule such as that of most
polymers, usually between carbon atoms. Saturation
makes the molecule less reactive and polymers less susceptible to degradation and cross-linking. Also called
Chemically Saturated Structure.
Chemical Unsaturation: Presence of double or triple
bonds in a chain organic molecule such as that of some
polymers, usually between carbon atoms. Unsaturation
makes the molecule more reactive, especially in freeradical addition reactions such as addition polymerization, and polymers more susceptibleto degradation, crosslinking, and chemical modification. Also called Polymer
Chain Unsaturation.
Chemically Saturated Structure: See Chemical Satu-
ration.
Chlorendic Polyester: A chlorendic anhydride-based unsaturated polyester.
Chlorinated Polyvinyl Chloride: Thermoplastic produced by chlorination of polyvinyl chloride. Has increased
glass transition temperature, chemical and fire resistance,
rigidity, tensile strength, and weatherability as compared
to PVC. Processed by extrusion, injection molding, casting, and calendering. Used for pipes, auto parts, waste
disposal devices, and outdoor applications. Also called
CPVC.
Chloroethyl Alcohol(2-): See Ethylene Chlorohydrin.
Chloroform: Trichloromethane, CHC1,. Chloroform is a
clear, colorless, volatile, nonflammable liquid with characteristic pungent smell. It is toxic and carcinogenic. Derived by chlorination of methane. Formerly used as an
anesthetic, it is now used mainly as a solvent and in organic synthesis to manufacture fluorocarbon plastics and
insecticides.
Chlorohydrins: Halohydrins with chlorine as a halogen atom. One of the most reactive of halohydrins.
Dichlorohydrins are used in the preparation of epichlorohydrins, important monomers in the manufacture of
epoxy resins. Mostchlorohydrins are reactive colorless liquids, soluble in polar solvents such as alcohols.
Note: Chlorohydrins are a class of organic compounds, not to be mixed with a specific member of this
class, l-chloropropane-2,3-diol sometimes called Chlorohydrin.
Chlorosulfonated Polyethylene Rubber: Thermosetting
elastomers containing 20-40% chlorine. Has good
weatherability and heat and chemical resistance. Used
for hoses, tubes, sheets, footwear soles, and inflatable
boats.
Cm Hg: A metric unit of measurement of pressure equal
to 13332.2 dynes/cm2 or 1333.22 pascals at 0°C. Onecentimeter of mercury is the pressure that would support
a column of mercury of length one centimeter and density
12,595 kg/m3 under the standard acceleration of free fall.
Used to denote the pressure of gases, vapors, and liquids.
Also called Centimeter of Mercury.
COC: Cyclic Olefin Copolymer.
CoF: Coefficient of Friction
Cocatalyst: SeeAccelerator.
Code of Federal Regulations 21 CFR 177: The 21 CFR
177 establishes specific guidelines for materials that come
into “indirect food contact”, i.e., materials that contact
food but are not ingredients. 21CFR 177 sets guidelines
for the manufacture of these materials and requires independent laboratory testing of the materials to ensure that
they do not exceed specified levels of extractables.
Coefficient of Friction (CoF): The coefficientof fiiction
is definedas the ratio ofthe weightof anobject being moved
along the surface of a specimen to the force that is required to maintain contact between the object and the surface.
Coefficient of Thermal Conductivity: The coefficient
of thermal conductivity, sometimes called the K-factor, is
defined as the quantity of heat that passes through a unit
cube of the substance in a given unit of time when the
difference in temperature of the two faces is 1 “C.
Coefficient of Thermal Expansion (Linear): The
coefficient of thermal expansion (linear) is the change in
length per unit length of material for a 1°C change in
temperature.
Coextruded Film: A film made by coextrusion of two or
more different or similar plastics through a single die with
two or more orifices arranged sothat the extrudates merge
and weld together into a laminar film before cooling. Each
ply of coextruded film imparts a desired property, such as
impermeability or resistance to some environment and
heat-sealability, usually unattainable with a single material.
Color Change: SeeDiscoloration.
Coloration: SeeDecoloration
Compatibilizer: A chemical compound used to increase
the compatibility or miscibility and to prevent the separation of the components in a plastic composition, such
as the compatibility of a resin and a plasticizer or of two
polymers in a blend. Block copolymers bearing blocks
similar to the polymers in the blend are often used as
compatibilizers in the latter case.
Concentration Units: The units for measuring the content of a distinct material or substance in a medium other
than this material or substance, such as solvent.
Note: The concentration units are usually expressed
in the units of mass or volume of substance per one unit
of mass or volume of medium. When the units of substance and medium are the same, the percentage is often
used.
Conditioning: Process of bringing the material or apparatus to a certain condition, e.g., moisture content or temperature, prior to further processing, treatment, etc. Also
called Conditioning Cycle.
Conditioning Cycle: See Conditioning.
Corona Discharge Treatment: Treating the surface of
an inert plastic such as polyolefin with corona discharge
to increase its affinityto inks, adhesives, or coatings.Plastic films are passed over a grounded metal cylinder
with a pointed high-voltage electrode above it to produce the discharge. The discharge oxidizes the surface,
making it more receptive to finishing. Also called Corona
Treatment.
Corona Treatment: See Corona Discharge Treatment
CONEG: The Coalition of Northeastern Governors is a
nonpartisan association of the Governors of the eight
Northeastern states that encourages intergovernmental
cooperation in the Northeast on issues relating to the
economic, environmental, and social well-being of the
Northeast states.
COPE: See Copolyester Ether.
Copolyester Ether: Copolyester ethers (COPE) are clear,
tough copolymers with elastomeric-like properties. They
provide strength and durability and resist puncturing.
Covulcanization: Simultaneous vulcanization of a blend
of two or more different rubbers to enhance their individual properties such as ozone resistance. Rubbers are
often modified to improve covulcanization.
CP: See Cellulose Propionate.
CPVC: See Chlorinated Polyvinyl chloride. 191
Cracking: Appearance of external andor internal cracks
in the material as a result of stress that exceeds the strength
of the material. The stress can be external andor internal
and canbe caused by a variety of adverse conditions: structural defects, impact, aging, corrosion, etc., or a combination thereof. Also called Cracks. See also Processing
Defects.
Cracks: See Cracking.
Crazes: See Crazing.
Crazing: Appearance of thin cracks on the surface of the
material or, sometimes, minute frost-like internal cracks,
as a result of stress that exceeds the strength of the material, impact, temperature changes, degradation, etc. Also
called Crazes.
Cross-linked Polyethylene: Polyethylene thermoplastics
partially photochemically or chemically cross-linked. Has
improved tensile strength, dielectric properties, and impact strength at low and elevated temperatures.
Cross-linking: Reaction of formation of covalent bonds
between chain-like polymer molecules or between polymer molecules and low-molecular compounds such as
carbon black fillers. As a result of cross-linking, polymers, such as thermosetting resins, may become hard and
infusible. Cross-linking is induced by heat, UV or electron-beam radiation, oxidation, etc. Cross-linking can be
achieved either between polymer molecules alone as in
unsaturated polyesters or with the help of multifunctional
cross-linking agents such as diamines that react with functional side groups of the polymers. Cross-linking can be
catalyzed by the presence of transition metal complexes,
thiols, and other compounds.
Crystal Polystyrene: See General Purpose Polystyrene.
Crystalline Melting Point: The temperatureofmelting of
the crystallite phase of a crystalline polymer. It is higher
than the temperature of melting of the surrounding amorphous phase.
Cycle Time: SeeProcessing Time.
Cyclic Compounds: A broad class of organic compounds
consisting of carbon rings that are saturated, partially
unsaturated, or aromatic, in which some carbon atoms
may be replaced by other atoms such as oxygen, sulfur,
and nitrogen.
D
d-Limonene: One of two optical isomers of limonene, a
naturally occurring terpene closely related to isoprene.
Limonene is a colorless liquid that oxidizes to film in air.
Derived from lemon, orange, and other essential oils. Used
as flavoring, fragrance, solvent, and wetting agent.
DAP: See Diallyl Phthalate Resins.
Dart Drop: See Impact Resistance, Dart Drop
Decoloration: Complete or partial loss of color of the
material as a result of degradation or removal of colored
substances present. Also called Decoloring.
Decoloring: SeeDecoloration.
Defects: See Processing Defects.
Deflection Temperature Under Load: SeeHeat Deflec-
tion Temperature.
Degradation: Loss or undesirable change in the properties, such as color,of a material as a result of aging, chemical reaction, wear, exposure, etc. See also Stability.
Diallyl Phthalate Resin: Thermoset supplied as diallyl
phthalate prepolymer or monomer. Hashigh chemical, heat
and water resistance, dimensional stability, and strength.
Shrinks during peroxide curing. Processed by injection,
compression, and transfer-molding. Used in glass-reinforced tubing, auto parts, and electrical components. Also
called DAP.
Dielectric Constant: The ability of an insulator to store
electrical energy can be measured through the dielectric
constant. Better insulating materials have lower dielectric constants.
Dielectric Strength: The maximum electric field strength
that an insulator can withstand intrinsically without breaking down, i.e., without experiencing failure of its insulating properties.
Differential Scanning Calorimeter: Used to determine
the specific heat of a specimen by measurement of the
thermal response of the unknown specimen as compared
with a standard when the two are heated uniformly at a
constant rate. The ratio of the departure of the standard
and unknown from the baseline is used to calculate the
specific heat of the unknown. Also called DSC.192
Diffusion: Spontaneous slow mixing of different substances in contact without influence of external forces.
E
EAA: See Ethylene Acrylic Acid Copolymer.
Diffusion Coefficient: Weight of a substance diffusing
through a unit area in a unit time per a unit concentration
gradient. Also called Diffusivity.
Diffusivity: SeeDiffusion CoefJicient.
Dihydric Alcohols: See Glycols
Dihydroxy Alcohols: See Glycols.
Dimethyl Ketone: SeeAcetone.
Dimensional Stability: Dimensional stability is often
represented as a percentage change in the specimen
shape when the specimen is subjected to varying degrees of stress for example: temperature, moisture or pressure.
DIN 53122: A German Standards Institute (Deutsches
Institut fuer Normen, DIN) standard test method for determining water vapor transmission of flat materials such
as plastic film and sheeting.
DIN 53380: A German Standards Institute (Deutsches
Institut fuer Normen, DIN) standard test method for determining gas permeability of flat materials such as plastic film and sheeting.
Discoloration: A change in color due to chemical or
physical changes in the material. Also called Color
Change.
Disperse Dyes: Nonionic dyes insoluble in water and
used mainly as fine aqueous dispersions in dying acetate, polyester, and polyamide fibers. A large subclass
of disperse dyes comprises low-molecular-weight aromatic
azo compounds with amino, hydroxy, and alkoxy groups
that fix on fibers by forming van der Waals and hydrogen
bonds.
Displacement: Process of removing one object, e.g., a
medium in an apparatus, or its part, and replacing it with
another. Also called Displacement Cycle.
Displacement Cycle: SeeDisplacement.
Dissipation Factor: The ratio of the power loss in a dielectric material to the total power transmitted through
the dielectric material.
ECTFE: See Ethylene Chlorotrifluoroethylene Copoly-
mer.
Elastic Modulus: The force needed to elongate a material, or the ratio of the applied stress to the change in shape
of an elastic body.
Elmendorf Tear: A measurement of the tear resistance
of sheet materials including paper, packaging, foils, textiles, non-wovens, and plastic films.
Elongation: The change in length (lengthening, stretch)
of a material when subjected to tensile stress.
Elongation at Break (ultimate tensile strength): Elongation at break isthe strain at failure, or the percent change
in length at failure. (IS0 527)
Elongation at Yield: Elongation at yield is the strain that
the material undergoes at the yield point, or the percent
change in length that occurs while the material is stressed
to its yield point.
EMA: Ethylene Methyl Acrylate.
EMAC: See Ethylene Methyl Acrylate Copolymer.
Embrittlement: A reduction or loss of ductility or toughness in materials such as plastics resulting from chemical
or physical damage.
EP: Ethylene Propene. SeeEPDMRubber.
EPDM: See EPDM Rubber.
EPDM Rubber: Sulfur-vulcanizable thermosetting elastomer produced from ethylene, propylene, and a small
amount of nonconjugated diene such as hexadiene. Has
good weatherability and chemical and heat resistance.
Used as impact modifiers and for weather stripping, auto
parts, cable insulation, conveyor belts, hoses, and tubing.
Also called EPDM.
Epoxides: Organic compounds containing three-membered cyclic group(s) in which two carbon atoms are linked
with an oxygen atom as in an ether. This group is called
an epoxy group and is quite reactive, allowing the use of
epoxides as intermediates in preparation of certain fluorocarbons and cellulose derivatives and as monomers in
DSC: See Differential Scanning Calorimeter. 193
preparation of epoxy resins. Also called Epoxy Compounds.
Epoxies: SeeEpoxy Resins.
Epoxy Compounds: SeeEpoxides.
Epoxy Resins: Thermosetting polyethers containing
cross-linkable glycidyl groups. Usually prepared by
polymerization of bisphenol A and epichlorohydrin or
reacting phenolic novolaks with epichlorohydrin. Can
be made unsaturated by acrylation. Unmodified varieties are cured at room or elevated temperatures with
polyamines or anhydndes. Bisphenol A epoxy resins have
excellent adhesion and very low shrinkage during curing.
Cured novolak epoxies have good W stability and dielectric properties. Cured acrylated epoxies have high
strength and chemical resistance. Processed by molding,
casting, coating, and lamination. Used as protective coatings, adhesives, potting compounds, and binders in laminates and composites. Also called Epoxies.
EPR: SeeEthylene Propene Rubber.
ESCR: Environmental-stress-crack resistance.
ETFE : SeeEthylene Tetrafluoroethylene Copolymer
Ethane: An alkane (saturated aliphatic hydrocarbon) with
two carbon atoms, CH,CH,. A colorless, odorless, flammable gas. Relatively inactive chemically. Obtained from
natural gas. Used in petrochemical synthesis and as fuel.
coatings and plastics, organic synthesis, artificial flavors,
and pharmaceuticals.
Ethyl Alcohol: An aliphatic alcohol, CH,CH,OH. A colorless, volatile, flammable liquid (autoignition temperature, 422°C). Toxic by ingestion at high concentrations.
Derived by catalytic hydration of ethylene, fermentation
of biomass such as grain, or enzymatic hydrolysis of cellulose. Used as an automotive fuel additive, in alcoholic
beverages, as solvent for resins and oils, in organic synthesis, cleaning compositions, cosmetics, antifreeze, and
antiseptic. Also called Ethanol.
Ethylene: An alkene (unsaturated aliphatic hydrocarbon)
with two carbon atoms, CH,=CH,. A colorless, highly
flammable gas with sweet odor (autoignition temperature,
543°C). Derivedby thermal crackingof hydrocarbon gases
or from synthesis gas. Used as monomer in polymer synthesis, refrigerant, and anesthetic. Also called Ethene.
Ethylene Acrylic Acid Copolymer: Specialtythermoplastic created by high-pressure copolymerization of ethylene
(E), methacrylic acid (MAA), or acrylic acid (AA). Also
called EAA.
Ethylene Acrylic Rubber: Copolymers of ethylene and
acrylic esters. Has good toughness, low temperature properties, and resistance to heat, oil, and water. Used in auto
and heavy equipment parts.
Ethylene Alcohol: SeeEthylene Glycol.
Ethylene Copolymers: SeeEthylene Polymers.
Ethanediol(l,2-): SeeEthylene Glycol.
Ethanol: SeeEthyl Alcohol.
Ethene: SeeEthylene.
Ethers: A class of organic compounds in which an oxygen atom is interposed between two carbon atoms in a
chain or a ring. Ethers are derived mainly by catalytic
hydration of olefins. The lower molecular weight ethers
are dangerous fire and explosion hazards.
Note: Major types of ethers include aliphatic, cyclic, and
polymeric ethers.
Ethyl Acetate: An ethyl ester of acetic acid,
CH,CO,CH,CH,. A colorless, fragrant, flammable liquid (autoignition temperature, 426°C). Toxic by inhalation and skin absorption. Derived by catalytic esterification of acetic acid with ethanol. Used as solvent in
Ethylene Methyl Acrylate Copolymer: Thermoplastic copolymers of ethylene with <40% methyl- acrylate. Has good dielectricproperties, toughness, thermal stability, stress crack resistance, and compatibility with other polyolefins. Transparency decreases with increasing content of acrylate. Processed by blown film extrusion and blow and injection molding. Used in heat-sealable films, disposable gloves, and packaging. Some grades are FDAapproved for food packaging. Also called EMAC. Ethylene Oxide: A colorless gas at room temperatures, ethylene oxide is used in a sterilization process. Ethylene Polymers: Ethylene polymers include ethylene homopolymers and copolymers with other unsaturated monomers, most importantly, olefins such as propylene and polar substances such as vinyl acetate. The properties and uses of ethylene polymers depend on the194 molecular structure and weight. Also called Ethylene Copolymers. Ethylene Propene Rubber: Stereospecific copolymers of ethylene with propylene. Used as impact modifiers for plastics. Also called EPR. Ethylene Tetrafluoroethylene Copolymer: Thermoplastic alternating copolymer of ethylene and tetrafluoroethylene. Has good impact strength, abrasion and chemical resistance, weatherability, and dielectric properties. Processed by molding, extrusion, and powder coating. Used in tubing, cables, pump parts, and tower packing in a wide temperature range. Also called ETFE. Ethylene Vinyl Acetate Copolymer: Athermoplasticprepared by hydrolysis of ethylene-vinylacetatepolymers. Has good barrier properties, mechanical strength, gloss, elasticity, weatherability, clarity, and abrasion resistance. Barrier properties and processibilityimprove with increasing content of ethylene due to lower absorptionof moisture.Ethylene contentofhigh-barriergrades range fiom32to 44mol%. Processed by extrusion, coating,blow and blow-film molding, and thermoforming. Used as packaging films and container liners. Also calledEVA. ETO: See Ethylene Oxide. EVA: SeeEthylene Mnyl Acetate Copolymer. EVOH: Ethylene Vinyl Alcohol Copolymer. Extenders: Relatively inexpensive resin, plasticizer, or filler such as carbonate used to reduce cost andor to improve processing of plastics, rubbers, or nonmetallic coatings. Extrusion Coating: Coating by extruding a layer of molten resin onto a substrate with sufficient pressure to bond. Used in coating paper and fabrics with polyolefins by extruding a web directly into the roller nip through which the substrate is passing. Extrusion Temperature: Temperature of the molten thermoplastic maintained in the extruder barrel during the extrusion by means of barrel heating and internal friction of the melt pushed along by a screw or a ram. The temperature may vary along the length of the barrel. F FEP: See Fluorinated Ethylene Propylene Copolymer: Fick’s First Law: A physics law that states that the volume (V) of a penetrant, such as gas, that penetrates a barrier wall is directly proportional to the area (A) of the wall, partial pressure differential (p) of the penetrant, and time (t); and inversely proportional to the wall thickness (s), if the wall is homogeneous in the direction of penetration. The coefficient P in the equation representing Fick’s first law, V = P . (A . p . t)/s, is the permeability coefficient. Fireproofing Agent: SeeFlame Retardant. Five-Membered Heterocyclic Compounds: A class of heterocyclic compounds containing rings that consist of five atoms. Five-Membered Heterocyclic Nitrogen Compounds: A class of heterocyclic compounds containing rings that consist of five atoms, some of which are nitrogen. Five-Membered Heterocyclic Oxygen Compounds: A class of heterocyclic compounds containing rings that consist of five atoms, some of which are oxygen. Flame-Retardant: A substance that reduce the flammability of materials such as plastics or textiles in which it is incorporated. There are inorganic flame retardants such as antimony trioxide (Sb,O,) and organic flame retardants such as brominated polyols. The mechanisms of flame retardation vary depending on the nature of material and flame retardant. For example, some flame retardants yield a substantial volume of coke on burning, which prevents oxygen from reaching inside the material and blocks hrther combustion. Also called fireproofing agent, flame retardant chemical additives, and ignition resistant chemical additives. Flame-Retardant Chemical Additives: See Flame Re- tardant. Flammability Classification: This classification system defines the level of ignition and burning resistance of a specimen. Flaw: See Processing Defects. Flexural Modulus: The ratio, within the elastic limit, of the applied stress on a test specimen in flexure, to the corresponding strain in the outermost fibers of the specimen.195 Flexural Strength: The strength of a material in bending, expressed as the stress on the outermost fibers of a bent test specimen, at the instant of failure. Fluorinated Ethylene Propylene Copolymer: Thermoplastic copolymer of tetrafluoroethylene and hexafluoropropylene. Has decreased tensile strength and wear and creep resistance, but good weatherability, dielectric properties, fire and chemical resistance, and friction. Decomposes above 204°C (400″F), releasing toxic products. Processed by molding, extrusion, and powder coating. Used in chemical apparatus liners, pipes, containers, bearings, films, coatings, and cables. Also called FEP. Fluoro Rubber: SeeFluoroelastomers. Fluoroelastomers: Fluorine-containing synthetic rubber with good chemical and heat resistance. Used in underhood applications such as fuel lines, oil and coolant seals, and fuel pumps, and as a flow additive for polyolefins. Also called Fluoro Rubber. Fluoroplastics: SeeFluoropolymers. Fluoropolymers: Polymers prepared from unsaturated fluorine-containing hydrocarbons. Has good chemical resistance, weatherability, thermal stability, antiadhesive properties, low friction, and flammability, but low creep resistance, strength, and difficulty processing. The properties vary with the fluorine content. Processed by extrusion and molding. Used as liners inchemical apparatus, in bearings, films, coatings, and containers. Also called Fluoroplastics. Fluorosilicones: Polymers with chains of alternating silicon and oxygen atoms and trifluoropropyl pendant groups. Most are rubbers. FMQ: SeeMethyljluorosilicones. Folding Endurance Test: The folding endurance test is a measure of strength in that a specimen under a constant tensile load is continually folded until it is severed. Formaldehyde: The simplest aldehyde, H,CO. A readily polymerizable, toxic, skin irritating, carcinogenic gas with strong, pungent odor (autoignition temperature, 430°C). Derived by oxidation of methanol or low-boiling olefins. Used as monomer in manufacture of phenolic, acetal, and amino resins; as fertilizer, disinfectant, reducing agent, biocide, sterilant, corrosion inhibitor; in wood products such as plywood, foam insulation, and organic synthesis as an intermediate. FPC: Flexible printed circuit. Fractional Melt Index Resin: Thermoplastics having a low melt index of4. These resins have higher molecular weights and are harder to extrude because of lower rate and greater force requirements compared to the lower molecular weight resins. They are mainly used for heavy duty applications such as pipe. Furnace Black: The most common type of carbon black made by burning vaporized heavy oil fractions in a furnace with 50% of the air required for complete combustion. It comes in high abrasion, fast extrusion, high modulus, general purpose, semireinforcing, conducting,high elongation, reinforcing,and fast-extruding grades, among others. Furnace black is widely used as a filler and pigment in rubbers and plastics. It reinforces, increases the resistance to W light, and reduces static charging. b Gas Black: See Channel Black. Gas-Permeability Coefficient: A measure of gas permeability of a barrier wall such as plastic film. Gas permeability coefficient, P, is a coefficient in Fick’s first law that states that the volume (V) of a substance that penetrates a barrier wall is directly proportional to the area (A) of the wall, partial pressure differential (p) of the penetrant, and time (t); and inversely proportional to the wall thickness (s), if the wall is homogeneous in the direction of penetration. Gas permeability coefficient depends on the test temperature. Gas-Transmission Rate: This is a measure of the steady state rate of transmission of a gas through plastics in the form of film, sheeting or laminates. General-Purpose Polystyrene: General-purpose polystyrene is an amorphous thermoplastic prepared by homopolymerization of styrene. Has good tensile and flexural strengths, high light transmission, adequate resistance to water, detergents, and inorganic chemicals. It is attached by hydrocarbons and has a relatively low impact resistance. Processed by injection molding and foam extrusion. Used to manufacture containers, health care items such as pipettes, kitchen and bathroom housewares, stereo and camera parts, and foam sheets for food packaging. Also called Crystal Polystyrene. Gloss: Measured on a glossmeter, gloss is a measure of the light reflected by the surface of a plastic film.196 Glycols: Aliphatic alcohols with two hydroxy groups attached to a carbon chain. Can be produced by oxidation of alkenes followed by hydration. Also called Dihydric Alcohols and Dihydroxy Alcohols. G U S : Generally Recognized as Safe. GTR: See Gas Transmission Rate. H H: See Hydrogen. Halogen Compounds: A class of organic compounds containing halogen atoms such as chlorine. A simple example is halocarbons but many other subclasses with various functional groups and of different molecular structure exist as well. Halohydrins: Halogen compounds that contain a halogen atom (s) and a hydroxy (OH) group (s) attached to a carbon chain or ring. Can be prepared by reaction of halogens with alkenes in the presence of water or by reaction of halogens with triols. Halohydrins can be easily dehydrochlorinated in the presence of a base to give an epoxy compound. Hard Clays: Sedimentary rocks composed mainly of fine clay mineral material without natural plasticity, or any compacted or indurated clay. Haze: Measured on a hazemeter, haze is the scattering of light as it passes through a transparent material, resulting in poor visibility andor glare. HDPE: See High Density Polyethylene. HDT: See Heat Deflection Temperature. He: See Helium. Heat Deflection Temperature: The heat deflection temperature is defined as the temperature at which a specimen deflects a specified amount under specific heat and load conditions. Heat-Seal Temperature: Temperature of a thermoplastic film or sheet required to join two or more films or sheets in contact by fusion. Helium (He): A chemically inert, tasteless, colorless, noncombustible monatomic gas. Helium is often used to characterize permeability of polymeric films, as carrier gas in gas chromatography,as inert gas shield in welding, in electricbulbs such as neon, as heat-transfer medium, in lasers, and as a process environment. Henry’s Law: A law that states that the weight of the gas that dissolves in a given quantity of liquid is proportional to the pressure of the gas above the liquid. The law holds true only for equilibrium conditions. Heptane: An alkane (saturated aliphatic hydrocarbon)with sixcarbon atoms,CH,(CH,),CH,. A volatile, colorless, flammableliquid (autoignition temperature, 222°C).Toxicby inhalation. Obtained by fiactionation of petroleum. Used as a solvent and in organic synthesis. Also calledn-Heptane. n-Heptane: SeeHeptane. Heterocyclic Compounds: A class of cyclic compounds containing rings with some carbon atoms replaced by other atoms such as oxygen, sulhr, and nitrogen. High Density Polyethylene: A linear polyethylene with density 0.94-0.97 g/cm3.Has good toughness at low temperatures, chemical resistance, dielectric properties, and high softening temperature, but poor weatherability. Processed by extrusion, blow and injection molding, and powder coating. Used in houseware containers, food packaging, liners, cable insulation, pipes, bottles, and toys. Also called HDPE. High Impact Polystyrene: See Impact Polystyrene. High-Molecular-Weight, Low Density Polyethylene: Thermoplastic with improved abrasion and stress crack resistance and impact strength, but poor processibility and reduced tensile strength. Also called HMWLDPE. HIPS: See Impact Polystyrene. HMWLDPE: See High Molecular Weight Low Density Polyethylene. Hot Fill: A process in which containers are filled with a hot liquid. Containers suitable for hot filling should be heat resistant. If they are made of plastic, it should be of a hot-fill grade. Hot-Tack Strength: The force required to separate amolten seal in heat-sealable thermoplastic films. It determines the rate at which the film can be sealed. Also called Ultimate Hot-Tack Strength.197 Hydrogen (H): A highly flammable diatomic gas, H,. Occurs on earth mainly in combined form, e.g., with oxygen in water (autoignition temperature, 580°C). Derived by steam reforming, gasification of coal, and other methods. Used as hydrogenating and reducing agent in chemical processes and as rocket fuel. Hydrophilic Starch Surface: SeeHydrophilic Surface. Hydrophilic Surface: Surface of a hydrophilic substance that has a strong ability to bind, adsorb, or absorb water; a surface that is readily wettable with water. Hydrophilic substances include carbohydrates such as starch. Also called hydrophilic starch surface. Hydroxy Compounds: A broad class of organic compounds that contain a hydroxy (OH) group(s) that is not part of another hnctional group such as carboxylic group. Also called Hydroxyl-containing Compounds. Hydroxy Group: See Hydroxyl Group. Hydroxyl Group: A combination of one atom of hydrogen and one atom of oxygen, -OH, attached by a single covalent bond to another atom, such as carbon, in a molecule of an organic or inorganic substance. It is a characteristic group of alcohols and hydroxides. Hydroxyl groups on the surface of a material usually make it hydrophilic. Hydroxyl groups are quite reactive, e.g., they readily undergo etherification or esterification. Also called Hydroxy Group. Hydroxyl-Containing Compounds: SeeHydroxy Com- pounds. I IEC: See International Electrotechnical Commission. Ignition-Resistant Chemical Additives: SeeFlame Re- tardant. Impact-Penetration Energy: The puncture impact system uses a swinging pendulum arm. A round test sample, clamped around its periphery, is impacted. The penetration energy is calculated fiom the force necessary to break the sample. and structural foam molding. Used in food packaging, kitchen housewares, toys, small appliances, personal care items, and audio products. Also called IPS, High Impact Polystyrene, HIPS, and Impact PS. Impact Resistance, Dart Drop: The impact resistance is derived from the mass of the dart and the drop height that cause the specimen to crack or rupture. The total energy impact measures the kinetic energy lost by the free-falling dart that passes through the film. Impact Resistance, Spencer Impact: The method of measuring impact resistance of a film while the film is under the strain rate conditions that closely approximate the strain rates that the material is subject to in end-use applications. International Electrotechnical Commission: This is a non-government organization that prepares and publishes international standards for all electrical, electronic and related matters, such as the assessment of conformity to standards. in. Hg: An English unit of measurement ofpressure equal to 3.3864 x le+04 dynes/cm2 or 249.089 pascals at 0°C (32°F). One inch of mercury is the pressure that would support a column of mercury of length one inch and density 12,595kg/m3 under the standard acceleration of free fall. Used to denote the pressure of gases, vapors, and liquids. Also called Inch of Mercury. Initial-Tear Resistance: The force required to initiate tearing of a flexible plastic film or thin sheeting at very low rates of loading, measured as maximum stress usually found at the onset of tearing. Also called Tear Resistance, initial. Ionomers: Thermoplastics containing a relatively small amount of pendant ionized acid groups. Has good flexibility and impact strength in a wide temperature range, puncture and chemical resistance, adhesion, and dielectric properties, but poor weatherability, fire resistance, and thermal stability. Processed by injection, blow, and rotational molding, blown film extrusion, and extrusion coating. Used in food packaging, auto bumpers, sporting goods, and foam sheets. Impact Polystyrene: A thermoplastic produced by polymerizing styrene dissolved in butadiene rubber. Impact Ips: SeeImpact Polystyrene. polystyrene has good high rigidity, ISO, International Organization for Standardization: and good low temperature impact strength, but poor bar- IS0 is the world’s largest developer of standards consisting of a network of the national standards institutes of 147 countries, on the basis of one member per country. rier properties, grease resistance, and heat resistance. Processed by extrusion, injection molding, thermoforming,198 IS0 1184: Plastics -Determination of Tensile Properties of Films or sheeting less than 1 mm thick. Isophthalate Polyester: An unsaturated polyester based on isophthalic acid. Izod: See Izod Impact Energy. Izod Impact: See Izod Impact Energy. Izod Impact Energy: The energy required to break a specimen equal to the difference between the energy in the striking member of the Izod-type impact apparatus at the instant of impact and the energy remaining after complete fracture of the specimen. Also called Izod Impact, Izod Impact Strength, and Izod. Izod Impact Strength: SeeIzod Impact Energy. Izod Impact Test: Izod impact is a test designed to determine the resistance of a plastic to the impact of a suddenly applied force. It is ameasure of impact strength determined by the difference in energy of a swinging pendulum before and after it breaks a notched specimen held vertically as a cantilever beam. J JIS: Japanese Industrial Standard. JIS C-2151: Testing methods of plastic films for electrical purposes. JIS C-23 18: Test method for Polyethylene terephthalate (PET) films for electrical purposes. JIS P-8116: Paper- determination of tearing resistance -Elmendorf tearing tester method. JIS 2-0208: Testing methods for determination of the water vapor transmission rate of moisture proof packaging materials (dish method). Lamellar Injection Molding: Injection molding of individual thermoplastics or their blends, e.g., with liquidcrystal polymers, that produces a lamellar (platelike crystallite) skin texture of the molding for decorative purposes or enhanced surface properties. LCP: SeeLiquid Crystal Polymers. LDPE: SeeLow Density Polyethylene. Linear Low Density Polyethylene: Linear polyethylenes with density 0.91-0.94 g/cm3. Has better tensile, tear, and impact strength, and crack-resistance properties, but poorer haze and gloss than branched low-density polyethylene. Processed by extrusion at increased pressure and higher melt temperatures compared to branched low-density polyethylene, and by molding. Used to manufacture film, sheet, pipe, electrical insulation, liners, bags, and food wraps. Also called LLDPE. Linear Polyethylenes: Linear polyethylenesarepolyolefms with linearcarbon chains. They areprepared by copolymerization of ethylene with small amounts of higher a-olefins suchas 1-butene.Linearpolyethylenesare stiff, tough, and have good resistance to environmental cracking and low temperatures. Processed by extrusion and molding. Used to manufacture film, bags, containers, liners, profiles, and pipe. Liquid Crystal Polymers: Thermoplastic aromatic copolyesters with highly ordered structure. Has good tensile and flexural properties at high temperatures, chemical, radiation and fire resistance, and weatherability. Processed by sintering and injection molding. Used to substitute ceramics and metals in electrical components, electronics, chemical apparatus, and aerospace and auto parts. Also called LCP. LLDPE: SeeLinear Low Density Polyethylene. LMDPE: See Linear Medium Density Polyethylene. K Kinetic Coefficient of Friction: The ratio of tangential force, which is required to sustain motion without acceleration of one surface with respect to another, to the normal force, which presses the two surfaces together. Also called Coefficient of Friction, and Coefficient of Friction, kinetic. Low Density Polyethylene: A branched-chain thermoplastic with density 0.91-0.94 g/cm3. Has good impact strength, flexibility, transparency, chemical resistance, dielectric properties, and low water permeability and brittleness temperature, but poor heat, stress cracking, fire resistance, and weatherability properties. Processed by extrusion coating, injection and blow-molding, and film extrusion. Can be cross-linked. Used in packaging and shrink films, toys, bottle caps, cable insulation, and coatings. Also called LDPE.199 M Macroscopic Properties: See Thermodynamic Proper- ties. Mass Spectrometry: A method of substance structure analysis based on sending an ionized beam of substance molecules or molecular fiagments through a magnetic field to achieve a separation depending on the mass-electric charge ratio of the particles. MD: Machine Direction. MBT: See Mercaptobenzothiazole (24. Mechanical Properties: Properties describing the reaction of physical systems to stress and strain. Metallocene-Catalyzed, Linear Low Density Polyeth- ylene: Linear low density polyethylene is produced with a metallocene catalyst. Melamine Resins: Thermosetting resins prepared by condensation of formaldehyde with melamine. Have good hardness, scratch and fire resistance, clarity, colorability, rigidity, dielectric properties, and tensile strength, but poor impact strength. Molding grades are filled. Processed by compression, transfer, and injection molding, impregnation, and coating. Used in cosmetic containers, appliances, tableware, electrical insulators, hrniture laminates, adhesives, and coatings. Mercaptobenzothiazole (2-): A nitrogen- and sulhr-containing polyheterocyclic organic thiol used as vulcanization accelerator for rubber. Requires zinc oxide as an activator. Its vulcanizates have a good aging resistance. A yellowish powder with distinctiveodor. Combustible. Also called MBT. Methane: An alkane (saturated aliphatic hydrocarbon) with one carbon atom, CH,. A colorless, odorless, highly flammable gas (autoignition temperature, 537°C). Reacts with chlorine in light. Occurs as natural and coal gas. Can be obtained synthetically from a mixture of carbon monoxide and hydrogen fiom steam treatmentof hot coal. Used in petrochemical synthesis, for manufacture of carbon black and chlorinated solvents, and as fuel. Methanol: See Methyl Alcohol. Methyl Alcohol: An aliphatic alcohol, CH,OH. A colorless, volatile, flammable liquid (autoignition point, 464°C). Toxic by ingestion. Derivedby catalytichydrogenation of carbon monoxide, oxidation of natural gas, or gasification of wood. Used as fuel, as solvent for cellulosic and other resins, and in organic synthesis for manufacture of formaldehyde and proteins. Also called Methanol. Methylfluorosilicones: Silicone rubbers containing pendant fluorine and methyl groups. Has good chemical and heat resistance. Used in gasoline lines, gaskets, and seals. Also called FMQ. Methylphenylsilicones: Silicone rubbers containingpendant phenyl and methyl groups.Has good resistance to heat, oxidation, and radiation, and compatibilitywith plastics. Methylsilicone: Silicone rubbers containing pendant methyl groups. Has good heat and oxidation resistance. Used in electrical insulation and coatings. Also called MQ. Methylvinylfluorosilicone: Silicone rubbers containing pendant vinyl, methyl, and fluorine groups. Can be additionally cross-linked via vinyl groups. Has good resistance to petroleum products at elevated temperatures. Methylvinylsilicone: Silicone rubbers containing pendant methyl and vinyl groups. Can be additionally cross-linked via vinyl groups. Vulcanized to high degrees of cross-linking. Used in sealants, adhesives, coatings, cables, gaskets, tubing, and electrical tape. Micron: A unit of length equal to 1E-06 meter. Its symbol is Greek small letter mu (p) or pm. Migration: A mass-transfer process in which the matter moves from one place to another usually in a slow and spontaneous fashion. In plastics and coatings, migration of pigments, fillers, plasticizers and other ingredients via diffusion or floating to the surface or through interface to other materials results in various defects called blooming, chalking, bronzing, flooding, and bleeding, etc. Mineral Acid: An inorganic, usually strong, acid such as sulfuric acid (H,SO,). Mineral-Salt Medium: A corrosive medium such as aqueous solution, containing mineral or inorganic salt such as sodium chloride (NaC1). Used in material testing, especially of anticorrosive properties. M.I.T.: Folding Test Apparatus automatically tests folding endurance properties of a wide range of materials.Modified Polyphenylene Ether: Thermoplastic polyphenylene ether alloys with impact polystyrene. Has good impact strength, resistance to heat and fire, but poor resistance to solvents. Processed by injection and structural foam molding and extrusion. Used in auto parts, appliances, and telecommunication devices. Also called MPE, MPO, and Modified Polyphenylene Oxide. Modified Polyphenylene Oxide: See Modified Polyphenylene Ether. Modulus of Elasticity: SeeElastic Modulus. Moisture Absorption: The moisture content of a product can be defined as the percentage weight of water in relation to the dry weight of the product. Molding Defects: Structural and other defects in material caused inadvertently during molding by using wrong tooling, process parameters, or ingredients. Also called molding flaw. See also Design, etc. Usually preventable. Molding Flaw: See Molding Defects. Molecular Weight: The sum of the atomic weights of all atoms in a molecule. Also called MW. Molecular-Weight Distribution: The relative amounts of polymeric molecules of different weights in a specimen. Note: The molecular-weight distribution can be expressed in terms of the ratio between weight- and number-average molecular weights. Also called Polydispersity, MWD, and Molecular Weight Ratio. Molecular-Weight Ratio: SeeMolecular- Weight Distri- bution. MPE: See ModiJied Polyphenylene ether. MPO: See ModiJied Polyphenylene ether: MQ: SeeMethylsilicone. Mulch Film: A film, usually dark colored PVC film, used insteadofmulch in agriculture, e.g., to preventh i t rot, runners, and weed growth in cultivation of strawberries. Multilayer Film: A thermoplastic film consisting of two or more different or similar films jointed together, e.g., by coextrusion or lamination, to attain special properties uncharacteristic for a conventional film. MW: SeeMolecular Weight MWD: SeeMolecular Weight Distribution. N N: See Nitrogen. Neoprene Rubber: Polychloroprene rubbers with good resistance to petroleum products, heat, ozone, weatherability, and toughness. Nitrile: Any one of a series of cyanogen compounds. Nitrile Rubber: Rubbers prepared by free-radical polymerization of acrylonitrile with butadiene. Has good resistance to petroleum products, heat, and abrasion. Used in fuel hoses, shoe soles, gaskets, oil seals, and adhesives. Nitroarylamine: A class of aromatic amines containing benzene ring(s) with nitro (NO2group substituent(s), such as nitroanline (O,NC,H,NH,). Used as organic intermediates (e.g., in dye synthesis) and antioxidants in propellants and plastics. Nitrogen (N): A colorless, odorless, combustible diatomic gas, N,. The major component (about 78 ~01%) of earth’s atmosphere. Derived from air by fractionation. Used in organic and inorganic synthesis, as inert medium, for food freezing and freeze drying, as food antioxidant, in fertilizers, and as a pressurizing gas. Nonelastomeric Thermoplastic Polyurethanes: See Rigid Thermoplastic Polyurethanes. Nonelastomeric Thermosetting Polyurethane: Curable mixtures of isocyanate prepolymers or monomers. Has good abrasion resistance and low-temperature stability, but poor heat, fire, and solvent resistance and weatherability. Processedby reaction injection and structural foam molding, casting, potting, encapsulation, and coating. Used in heat insulation, auto panels and trim, and housings for electronic devices. Notch effect: The effectofthe presence of specimen notch or its geometry on the outcome of a test such as an impact strength test of plastics. Notching results in local stresses and accelerates failure in both static and cycling testing (mechanical, ozone cracking, etc.). Nylon: Thermoplastic polyamides often prepared by ring-opening polymerization of lactim. Has good resistance to most chemicals, abrasion, and creep, good impact and tensile strengths, barrier properties, and low friction, but poor resistance to moisture and light. Has201 high mold shrinkage. Processed by injection, blow and rotational molding, extrusion, and powder coating. Used in fibers, auto parts, electrical devices, gears, pumps, appliance housings, cable jacketing, pipes, and films. Nylon 11: Thermoplastic polymer of 1l-aminoundecanoic acid. Has good impact strength, hardness, abrasion resistance, processability, and dimensional stability. Processed by powder coating, rotational molding, extrusion, and injection molding. Used in electric insulation, tubing, profiles, bearings, and coatings. Nylon 12: Thermoplastic polymeroflauric lactam.Has good impact strength, hardness, abrasion resistance, and dimensional stability. Processed by powder coating, rotational molding, extrusion, and injection molding. Used in sporting goods and auto parts. Nylon 46: Thermoplastic copolymer of 2-pyrrolidone and caprolactam. Nylon 6: Thermoplastic polymer of caprolactam. Has good weldability and mechanical properties but rapidly picks up moisture which results in strength losses. Processed by injection, blow, and rotational molding and extrusion. Used in fibers, tire cord, and machine parts. Nylon 6/10: Thermoplastic polymer of hexamethylenediamine and sebacic acid. Has decreased melting point and water absorption and good retention of mechanical properties. Processed by injection molding and extrusion. Used in fibers and machine parts. Nylon 6/12: Thermoplasticpolymer of 1,12-dodecanedioic acid and hexamethylenediamine. Nylon 66: Thermoplastic polymer of adipic acid and hexamethylenediamine. Has good tensile strength, elasticity, toughness, heat resistance, abrasion resistance, and solvent resistance, but low weatherability and color resistance. Processed by injection molding and extrusion. Used in fibers, bearings, gears, rollers, and wire jackets. Nylon 6/66: Thermoplastic polymer of adipic acid, caprolactam, and hexamethylenediamine. Has good strength, toughness, abrasion, and fatigue resistance, and low friction, but high moisture absorption and low dimensional stability. Processed by injection molding and extrusion. Used in electrical devices and auto and mechanical parts. Nylon MXD6: Thermoplastic polymer of m-xylyleneadipamide. Has good flexural strength and chemical resistance, but decreased tensile strength. 0 Olefin Resins: SeePolyoleJins. Olefinic Resins: SeePolyoleJins. Olefinic Thermoplastic Elastomers: Blends of EPDM or EP rubbers with polypropylene or polyethylene, optionally cross-linked. Has low density, good dielectric and mechanical properties, and processibility,but low oil resistance and high flammability. Processed by extrusion, inj ection and blow-molding, thermoforming, and calendering. Used in auto parts, construction, wire jackets, and sporting goods. Also called TPO. ON: See Oriented Nylon. OPET: See Oriented Polyester. OPP: See Oriented Polypropylene. Organic Compounds: See Halogen Compounds. Also called Organic Substances. Organic Substances: See Organic Compounds. Orientation: A process of drawing or stretching of asspun synthetic fibers or hot thermoplastic films to orient polymer molecules in the direction of stretching. The fibers are drawn uniaxially and the films are stretched either uniaxially or biaxially (usually longitudinally or longitudinally and transversely, respectively). Oriented fibers and filmshave enhanced mechanical properties. The films will shrink in the direction of stretching, when reheated to the temperature of stretching. Oriented Film: Film that has been oriented either monoaxially (in one direction), the direction of tear, or biaxially (in two directions), to achieve strength and stiffness. Monoaxially oriented tape exhibits stronger MD (machine direction) tensile properties than biaxially oriented tape. Materials that have been oriented bear an 0 before the acronym (e.g., OPS, oriented polystyrene). Oriented Nylon: See Oriented Film. Also called ON. Oriented Polyester: See Oriented Film. Also called OPET. Oriented Polystyrene: See Oriented Film. Also called OPS.202 Oriented Polypropylene: A grade of polypropylene film hot stretched uniaxially or biaxially (usually longitudinally or longitudinally and transversely, respectively) to orient polymer molecules in the direction of stretching. Oriented films have enhanced mechanical properties. They will shrink in the direction of stretching when reheated, e.g., during heat-sealing. Also called OPP. OTR: Oxygen Transmission Rate. condense the monomer and deposit it as a polymer in the form of a thin, uniform coating on a substrate such as paper or fabric. pascal (Pa): An SI unit of measure of pressure equal to the pressure resulting from a force of one newton acting uniformly over an area of one square meter. Used to denote the pressure of gases, vapors, or liquids and the strength of solids. Oxazolines: Heterocyclic compounds containing fivemembered rings in which one carbon is replaced with an oxygen atom and another with a nitrogen atom. Oxazolines are colorless liquids soluble in organic solvents and water. Used as intermediates, e.g., in synthesisof surfactants. PB: See Polybutene. PBI: SeePolybenzimidazoles. PBT: See Polybutylene Terephthalate. Ozone: Anallotropic form of oxygen, 0,. Unstable gas formed naturally, in air by lightening, in stratosphere by the UV portion of solar radiation, or formed as a result of combustion of fossil fuels, i.e., in exhaust gases from automobiles. 0, is an active oxidizing agent that accelerates deterioration of rubber. P late. PC: SeePolycarbonates. PCT: SeePolycyclohexylenedimethylene Terephthalate. PCTFE: SeePolychlorotrifluoroethylene. PCTG: See Polycyclohexylenedimethylene Terephtha- PA: See Polyamide. PABM: SeePolyaminobismaleimide resins. PE: See Polyethylene. PE Copolymer: SeePolyethylene Copolymer. Paraffinic Plasticizer: Plasticizers for plastics comprising liquid or solid long-chain alkanes or paraffins (saturated linear or branched hydrocarbons). Partial Pressure: The pressure that would be exerted by a gas in a gas mixture if it were present alone. PEBA: See Polyether Block PEEK: SeePolyetheretherketone. PEI: SeePolyetherimides, Parts Per Hundred: A relative unit of concentration, parts of one substance per 100 parts of another. Parts can be measured by weight, volume, count, or any other suitable unit of measure. Used often to denote composition of a blend or mixture, such as plastic, in terms of the parts of a minor ingredient, such as plasticizer, per 100 parts of a major, such as resin. Parts Per Hundred Million: A relative unit of concentration, parts of one substance per 100 million parts of another. Parts can be measured by weight, volume, count, or any other suitable unit of measure. Used often to denote very small concentration of a substance, such as impurity or toxin, or in a medium, such as air. Also called P P h . Parylene: Thermoplastics made by vapor-phase polymerization of p-xylene. Hot p-xylene vapors are cooled to PEK: SeePolyetherketone. PEN: See Polyethylene Napthalate. Pendant Aromatic Rings: Aromatic (conjugated unsaturated rings such as those of benzene, C6H6)rings attached to the main chain of a polymer molecule. Pendulum Impact Resistance: SeeImpact Resistance, Spencer Impact Penetrant: A substance such as gas that penetrates or is capable of penetrating through another substance, usually a solid barrier wall such as plastic film. Also called Permeant. Pentaerythritol: A polyol, C(CH,OH),, prepared by reaction of acetaldehyde with an excess formaldehyde203 in alkaline medium. Used as plasticizer and as monomer in alkyd resins. Perchloroethylene: See Tetrachloroethylene. Perfluoroalkoxy Resins: Thermoplastic polymers of perfluoroalkoxyethylenes. They have good creep, heat, and chemical resistance and processibility, but low compressive and tensile strengths. Processed by molding, extrusion, rotational molding, and powder coating. Used in films, coatings, pipes, containers, and chemical apparatus linings. Also called PFA. Perm: An English unit of measurement of permeability of material in terms of the permeability coefficient. It is equal to the volume of penetrant in cubic feet that penetrates an area of one square foot of a barrier wall one foot thick per day at a pressure differential of one poundforce per square inch. Permanent Gas: Gases that become liquid at pressures and temperatures far from normal (1 atm and O”C, respectively). These gases include air, oxygen, argon, and carbon dioxide. Phenolic Resins: Thermoset polymers of phenols with excess or deficiency of aldehydes, mainly formaldehyde, to give resole or novolak resins, respectively. Heat-cured resins have good dielectric properties, hardness, thermal stability, rigidity, and compressive strength, but poor chemical resistance and dark color. Processed by coating, potting, compression, transfer, or injection molding and extrusion. Used in coatings, adhesives, potting compounds, handles, electrical devices, and auto parts. Phthalocyanine: A nitrogen-containing heterocyclic organic compound, (C6H4C2N)2(C6H4C2NH)2N4, belonging to the group of benzoporphyrins and comprising four isoindole groups jointed by four nitrogen atoms. Readily forms salt complexes with copper, chromium, iron, etc., that are important green and blue dyes and pigments. Has high light and chemical stability. Used in coatings, plastics, and textiles. Pinhole Flex: Pinhole flex is the testing by which flex resistance of a specimen can be determined. Pinhole formation is the criterion presented for measuring failure. PI: SeePolyimides. Permeant: SeePenetrant. PES: SeePolyethersulfone. PET SeePolyethylene Terephthalate. PETG: See Polycyclohexylenedimethylene Ethylene Terephthalate. PFA: SeePerfluoroalkoxy Resins. Plasticizer: A substance incorporated into a material such as plastic or rubber to increase its softness, processability, and flexibility via solvent or lubricating action or by lowering its molecular weight. Plasticizerscan lower melt viscosity, improve flow and increase low-temperature resilience of material. Most plasticizers are nonvolatile organic liquids or low-melting-point solids, such as dioctyl phthalate or stearic acid. They have to be non-bleeding, nontoxic, and compatible with material. Sometimes plasticizers play a dual role as stabilizers or cross-linkers. Phase Transition: SeePhase Transition Properties. Plastics: SeePolymers. Phase-Transition Point: The temperature at which a phase transition occurs in a physical system such as material. Note: An example of phase transition is glass transition. Also called Phase-Transition Temperature, Transition Point, and Transition Temperature. Phase-Transition Properties: Properties of physical systems such as materials associated with their transition fiom one phase to another, e.g., from liquid to solid phase. Also called Phase Transition. Phase-Transition Temperature: See Phase-Transition Point. PMMA: SeePolymethyl Methacrylate. PMP: See Polymethylpentene. Polyacrylates: SeeAcrylic Resins. Polyallomer: Crystalline thermoplastic block copolymers of ethylene, propylene, and other olefins. Has good impact strength, flex life, and low density. Polyamide Thermoplastic Elastomers: Copolymers containing soft polyether and hard polyamide blocks. Has good chemical, abrasion, and heat resistance, impact strength, and tensile properties. Processed by injectionand blow-molding and extrusion. Used in sporting goods, auto parts, and electrical devices. Also called Polyamide TPE. Polyamide TPE: See Polyamide Thermoplastic Elas- tomers. Polyamides: Thermoplastic aromatic or aliphatic polymer of dicarboxylic acids and diamines, of amino acids, or of lactams. Has good mechanical properties, chemical resistance, and antifriction properties. Processed by extrusion and molding. Used in fibers and molded parts. Also called PA. Polyaminobismaleimide Resins: Thermoset polymers of aromatic diamines and bismaleimides. Has good flow and thermochemical properties and flame and radiation resistance. Processed by casting and compression molding. Used in aircraft parts and electrical devices. Also called PABM. Polyarylamides: Thermoplastic crystalline polymers of aromatic diamines and aromatic dicarboxylic anhydrides. Has good heat, fire, and chemical resistance, property retention at high temperatures, dielectric and mechanical properties, and stiffness, but poor light resistance and processibility. Processed by solution casting, molding, and extrusion. Used in films, fibers, and molded parts. Polyarylsulfone: Thermoplastic aromatic polyetherpolysulfone. Has good heat, fire, and chemical resistance, impact strength, resistanceto environmental stress cracking, dielectric properties, and rigidity. Processed by injection and compression molding and extrusion. Used in circuit boards, lamp housings, piping, and auto parts. Polybenzimidazoles: Mainly polymers of 3,3′,4,4′- tetraminonbiphenyl (diaminobenzidine) and diphenyl isophthalate. Has good heat, fire, and chemical resistance. Used as coatings and fibers in aerospace and other hightemperature applications. Also called PBI. Polybutene: Polybutene-1 (PB-l), is a polyolefin, or unsaturated polymer, that is expressed as C,H,,. Polybutylene Terephthalate: Thermoplastic polymer of dimethyl terephthalate and butanediol. Has good tensile strength, dielectric properties, and chemical and water resistance, but poor impact strength and heat resistance. Processed by injection and blow-molding, extrusion, and thermoforming. Used in auto body parts, electrical devices, appliances, and housings. Also called PBT. Polycarbodimide: Polymers containing -N=C=N- linkages in the main chain, typically formedby catalyzed polycondensation of polyisocyanates. They are used to prepare open-celled foams with superior thermal stability. Sterically hindered polycarbodimides are used as hydrolytic stabilizers for polyester-based urethane elastomers. Polycarbonate: SeePolycarbonates. Polycarbonate Polyester Alloys: High-performance thermoplastics processed by injection and blow-molding. Used in auto parts. Polycarbonate resins: See Polycarbonates Polycarbonates: Polycarbonates are thermoplastics prepared by either phosgenation of dihydric aromatic alcohols such as bisphenol A or by transesterification of these alcohols with carbonates, e.g., diphenyl carbonate. Polycarbonates consistof chains with repeating carbonyldioxy groups and can be aliphatic or aromatic. Has very good mechanical properties, especially impact strength, low moisture absorption and good thermal and oxidative stability. They are self-extinguishing and some grades are transparent. Polycarbonates have relatively low chemical resistance and resistance to stress cracking. Processed by injection and blow-molding, extrusion, and thermoforming at relatively high processing temperatures. Used in telephone parts, dentures, business machine housings, safety equipment, nonstaining dinnerware,foodpackaging, etc. Also called Polycarbonate, PC, and Polycarbonate Resins. Polychlorotrifluoroethylene: Thermoplastic polymer of chlorotrifluoroethylene. Has good transparency, barrier properties, tensile strength, and creep resistance, modest dielectric properties and solvent resistance, and poor processibility. Processed by extrusion, injection and compression molding, and coating. Used in chemical apparatus, low-temperature seals, films, and internal lubricants. Also called PCTFE. Polycyclohexylenedimethylene Ethylene Terephtha- late: Thermoplastic polymer of cyclohexylenedimethylenediol, ethylene glycol, and terephthalic acid. Has good clarity, stiffness, hardness, and low-temperature toughness. Processed by injection and blow-molding and extrusion. Used in containers for cosmetics and foods, packaging film, medical devices, machine guards, and toys. Also called PETG. Polycyclohexylenedimethylene Terephthalate: Thermoplastic polymer of cyclohexylenedimethylenediol and205 terephthalic acid. Has good heat resistance. Processed by molding and extrusion. Also called PCT and PCTG. Polydispersity: SeeMolecular Weight Distribution. Polyester Resins: SeePolyesters. Polyester Thermoplastic Elastomers: Copolymers containing softpolyether and hard polyester blocks. Has good dielectric strength, chemical and creep resistance, dynamic performance, appearance, and retention of properties in a wide temperature range, but poor light resistance. Processed by injection, blow and rotational molding, extrusion casting, and film blowing. Used in electrical insulation, medical products, auto parts, and business equipment. Also called Polyester TPE. Polyester TPE: SeePolyester Thermoplastic Elastomers. Polyesters: A broad class of polymers usually made by condensation of a diol with dicarboxylic acid or anhydride. Polyesters consist of chains with repeating carbonyloxy group and can be aliphatic or aromatic. There are thermosetting polyesters, such as alkyd resins and unsaturated polyesters, and thermoplastic polyesters such as PET. The properties, processing methods, and applications of polyesters vary widely. Also called Polyester Resins. Polyether Block Amide: Polyether Block Amide is a thermoplastic elastomer made of a flexible polymer and a rigid polyamid. Polyetheretherketone: Semicrystalline thermoplastic aromatic polymer. Has good chemical, heat, fire, and radiation resistance, toughness, rigidity, bearing strength, and processibility. Processed by injection molding, spinning, cold forming, and extrusion. Used in fibers, films, auto engine parts, aerospace composites, and electrical insulation. Also called PEEK. Polyetherimides: Thermoplastic cyclized polymers of aromatic diether dianhydrides and aromatic diamine. Has good chemical, creep, and heat resistance, and dielectric properties. Processed by extrusion, thermoforming, and compression, injection, and blowmolding. Used in auto parts, jet engines, surgical instruments, industrial apparatus, food packaging, cookware, and computer disks. Also called PEL Polyetherketone: Thermoplastic; has good heat and chemical resistance and thermal stability. Used in advanced composites, wire coating, filters, integrated circuit boards, and bearings. Also called PEK. Polyethersulfone: Thermoplastic aromatic polymer; has good heat and fire resistance, transparency, dielectric properties, dimensional stability, rigidity, andtoughness, but poor solvent and stress cracking resistance, processibility, and weatherability. Processed by injection, blow, and compression molding and extrusion. Used in high temperature applications, electrical devices, medical devices, housings, and aircraft and auto parts. Also called PES. Polyethylene Copolymer: Thermoplastic polymers of ethylene with other olefins such as propylene. Processed by molding and extrusion. Also called PE Copolymer. Polyethylene Napthalate: Polyethylene Napthalate (PEN), a new generation polymer, is a high-performance member of the polyester family. Polyethylene Terephthalate: Thermoplastic polymer of ethylene glycol with terephthalic acid. Has good hardness, wear and chemical resistance, dimensional stability, and dielectric properties. High-crystallinity grades have good tensile strength and heat resistance. Processed by injection and blow-molding and extrusion. Used in fibers, food packaging (films, bottles, trays), magnetic tapes, and photo films. Also called PET. Polyimides: Thermoplastic aromatic cyclized polymers of trimellitic anhydride and aromatic diamine. Has good tensile strength, dimensional stability, dielectric and barrier properties, and creep, impact, heat, and fire resistance, but poor processibility. Processed by compression and injection molding, powder sintering, film casting, and solution coating. Thermoset uncyclized polymers are heat curable and have good processability. Processed by transfer and injection molding, lamination, and coating. Used in jet engines, compressors, sealing coatings, auto parts, and business machines. Also called PI. Polymer Chain Unsaturation: See Chemical Unsaturation. Polymers: High-molecular-weight organic or inorganic compounds, the molecules comprise linear, branched, crosslinked, or otherwise shaped chains of repeating molecular groups. Synthetic polymersare preparedby polymerization of one or more monomers.The monomers are low-molecular-weight substances with one or more reactive bonds or functionalgroups. Also calledresins, plastics. Polymethyl Methacrylate: Thermoplastic polymer of methyl methacrylate. Has good transparency, weatherability, impact strength, and dielectric properties.206 Processed by compression and injection molding, casting, and extrusion. Used in lenses, sheets, airplane canopies, signs, and lighting fixtures. Also called PMMA. Polymethylpentene: Thermoplastic stereoregularpolyolefin obtained by polymerizing 4-methyl-1-pentene based on dimerization of propylene; has low density, good transparency, rigidity, dielectric and tensile properties, and heat and chemical resistance. Processed by injection and blowmolding and extrusion. Used in laboratory ware, coated paper, light fixtures, auto parts, and electrical insulation. Also called PMP. Polyolefin Plastomers: Polyolefin Plastomers are elastomeric polymers made of polypropylene and ethylenepropylene diene rubber. In general, a plastomer provides an excellent combination of mechanical, thermal, and chemical properties expected of conventional thermoset rubber. Polyolefin Resins: SeePolyoleJins. Polyolefins: A broad class of hydrocarbon-chain elastomers or thermoplastics usually prepared by addition (co)polymerization of alkenes such as ethylene. There are branched and linear polyolefins and some are chemically or physically modified. Unmodified polyolefinshave relatively low thermal stability and a nonporous, nonpolar surface with poor adhesive properties. Processed injection, blow, and rotational molding and extrusion. Polyolefins are used more andhave more applications than any other polymers. Also called Olefinic Resins, Olefin Resins, and Polyolefin Resins. Polyphenylene Ether Nylon Alloys: Thermoplastics;has improved heat and chemical resistance and toughness. Processed by molding and extrusion. Used in auto body parts. Polyphenylene Sulfide: High-performance engineering thermoplastic; has good chemical, water, fire, and radiation resistance, dimensional stability, and dielectric properties, but decreased impact strength and poor processability. Processed by injection, compression, and transfer molding and extrusion. Used in hydraulic components, bearings, electronic parts, appliances, and auto parts. Also called PPS. Polyphenylene Sulfide Sulfone: Thermoplastic; has good heat, fire, creep, and chemical resistance and dielectric properties. Processed by injection molding. Used in electrical devices. Also called PPSS. Polyphthalamide: Thermoplastic polymer of aromatic diamine and phthalic anhydride. Has good heat, chemical, and fire resistance, impact strength, retention of properties at high temperatures, dielectric properties, and stiffness, but decreased light resistance and poor processability. Processed by solution casting, molding, and extrusion. Used in films, fibers, and molded parts. Also called PPA. Polypropylene: Thermoplastic polymer of propylene. Has low density and good flexibility and resistance to chemicals, abrasion, moisture, and stress cracking, but decreased dimensional stability, mechanical strength, and light, fire, and heat resistance. Processed by injection molding, spinning, and extrusion. Used in fibers and films for adhesive tapes and packaging. Also called PP. Polypyrrole: A polymer of pyrrole, a five-membered heterocyclic substance with one nitrogen and four carbon atoms and with two double bonds. The polymer can be prepared via electrochemical polymerization. Polymers thus prepared are doped by electrolyte anion and are electrically conductive. Polypyrrole is used in lightweight secondary batteries, as electromagnetic interference shielding, anodic coatings, photoconductors, solar cells, and transistors. Polystyrene: Thermoplastics produced by polymerization of styrene with or without modification (e.g., by copolymerization or blending) to make impact-resistant or expandable grades. Has good rigidity, high dimensional stability, low moisture absorption, optical clarity, high gloss, and good dielectric properties. Unmodified polystyrenes have poor impact strength and resistance to solvents, heat, and UV radiation. Processed by injection molding, extrusion, compression molding, and foam molding. Used widely in medical devices, housewares, food packaging, electronics, and foam insulation. Also called Polystyrenes, PS, and Polystyrol. Polystyrenes: SeePolystyrene Polystyrol: SeePolystyrene. Polysulfones: Thermoplastics, often aromatic with ether linkages; has good heat, fire, and creep resistance, dielectric properties, transparency, but poor weatherability, processability, and stress cracking resistance. Processed by injection, compression, and blow-molding and extrusion. Used in appliances, electronic devices, auto parts, and electric insulators. Also called PSO.207 Polytetrafluoroethylene: Thermoplastic polymer of tetrafluoroethylene; has good dielectric properties, chemical, heat, abrasion, and fire resistance, antiadhesive properties, impact strength, and weatherability, but decreased strength, processability, barrier properties, and creep resistance. Processed by sinter molding and powder coating. Used in nonstick coatings, chemical apparatus, electrical devices, bearings, and containers. Also called PTFE. Polyurethane Resins: SeePolyurethanes. Polyurethanes: A broad class of polymers consisting of chains with a repeating urethane group, prepared by condensation of polyisocyanates with polyols, e.g., polyester or polyether diols. PUSmay be thermoplastic or thermosetting, elastomeric or rigid, cellular or solid, and offer a wide range of properties depending on composition and molecular structure. Has high abrasion resistance, good retention of properties at low temperatures, and good foamability, but poor heat resistance, weatherability, and resistance to solvents. PUS are flammable and can release toxic substances. Thermoplastic PUS are not cross-linked and are processed by injection molding and extrusion. Thermosetting PUScan be cured at relatively low temperatures and give foams with good heat insulating properties. They are processed by reaction injection molding, rigid and flexible foam methods, casting, and coating. PUSare used in load bearing rollers and wheels, acoustic clampingmaterials, sporting goods, seals and gaskets, heat insulation, potting, and encapsulation. Also called PUR, PU, Urethane Polymers, Urethane Resins, Urethanes, and Polyurethane Resins. Polyvinyl Alcohol: PolyvinylAlcohol (PVOH)is a watersoluble synthetic polymer made by alcoholysis of polyvinyl acetate (PVA)and is available hydrolyzed, or partially hydrolyzed, and as a copolymer. Polyvinyl Chloride: Thermoplastic polymer of vinyl chloride, available in rigid and flexible forms. Has good dimensional stability, fire resistance, and weatherability, but decreased heat and solvent resistance and high density. Processed by injection and blow-molding, calendering, extrusion, and powder coating. Used in films, fabric coatings, wire insulation, toys, bottles, and pipes. Also called PVC. Polyvinyl Fluoride: Crystalline thermoplastic polymer of vinyl fluoride; has good toughness, flexibility, weatherability, and low-temperature and abrasion resistance. Processed by film techniques. Used in packaging, glazing, and electrical devices. Also called PVF. Polyvinylidene Chloride: Stereoregular thermoplastic polymer of vinylidene chloride; has good abrasion and chemical resistance and barrier properties. Vinylidene chloride (VDC) content always exceeds 50%. Processed by molding and extrusion. Used in food packaging films, bag liners, pipes, upholstery, fibers, and coatings. Also called PVDC. Polyvinylidene Fluoride: Thermoplastic polymer of vinylidene fluoride; has good strength, processability, wear, fire, solvent, and creep resistance, and weatherability, but decreased dielectric properties and heat resistance. Processed by injection and transfer molding, extrusion, and powder coating. Used in electrical insulation, pipes, chemical apparatus, coatings, films, containers, and fibers. Also called PVDF. POP: SeePolyoleJin Plastomers. PP: See Polypropylene. PPA: See Po lyphthalam ide. pphm: SeeParts Per Hundred Million. ppm: A unit for measuring small concentrations of material or substance as the number of its parts (arbitrary quantity) per million parts of medium consisting of another material or substance. PPS: SeePolyphenylene SulJide. PPSS: See Polyphenylene SulJide Sulfone. Pressure: Stress exerted equally in all directions. Also called Processing Pressure. Pressure Differential: SeePressure Gradient. Pressure Gradient: The rate of decrease of pressure in space at a fixed time, or the magnitude of this decrease. The permeation coefficient of gases through a barrier wall such as plastic film increases with increasing pressure gradient, which is a driving force of the process, and, therefore, should be stated for the coefficient valuesto be meaningful. Also called Pressure Differential. Prevulcanization: See Scorching. Process Characteristics: SeeProcessing Parameters. Process Conditions: SeeProcessing Parameters. 208 Process Media: See Processing Agents Process Parameters: SeeProcessing Parameters. Process Pressure: See Processing Pressure Process Rate: SeeProcessing Rate. Process Speed: SeeProcessing Rate. Process Time: SeeProcessing Time. Process Velocity: See Processing Rate Processing Additives: See Processing Agents. Processing Agents: Agentsormedia used in the manufacture, preparation, and treatment of a material or article to improve its processing or properties. The agents often become a part of the material. Also called Process Media, Processing Aids, and Processing Additives. Processing Rate: Speed of the process in manufacture, preparation, and treatment of a material or article. It usually denotes the change in aprocessparameter per unit of time or the throughput speedof material in a unit of weight, volume, etc., per unit of time. Also called Process Speed, Process Velocity, and Process Rate. Processing Time: Time required for the completion of a process in the manufacture, preparation, and treatment of a material or article. Also called Process Time, and Cycle Time. Promoter: SeeAccelerator Propane: An alkane (saturated aliphatic hydrocarbon) with three carbon atoms, CH,CH,CH,. A colorless, flammable gas (autoignition temperature, 467°C). Relatively inactive chemically. Obtained from petroleum or natural gas. Used in petrochemical synthesis, as fuel, aerosol propellant, and refrigerant. Propanone (2-): SeeAcetone. Processing Aids: See Processing Agents. Propene: See Propylene. Processing Defects: Structural and other defects in material or article caused inadvertently during manufacturing, preparation, and treatment processes by using wrong tooling, process parameters, ingredients, part design, etc. Usually preventable.Also called Processing Flaw, Defects, and Flaw. See also Cracking. Propylene: An alkene (unsaturated aliphatic hydrocarbon) with three carbon atoms, CH,=CHCH,. A colorless, highly flammable gas (autoignition temperature, 497°C). Derived by thermal cracking of ethylene or from naphtha. Used as monomer in polymer and organic synthesis. Also called Propene. Processing Flaw: SeeProcessing Defects. PS: SeePolystyrene. Processing Methods: Method names and designations for material or article manufacturing, preparation, and treatment processes. Note: Both common and standardized names are used. Also called Processing Procedures. Processing Parameters: Measurable parameters such as temperature prescribed or maintained during material or article manufacture, preparation, and treatment processes. Also called Process Characteristics, Process Conditions, and Process Parameters. Processing Pressure: Pressure maintained in an apparatus during material or article manufacture, preparation, and treatment processes. Also called Process Pressure. See also Pressure. Processing Procedures: SeeProcessing Methods. PSO: See Polysulfones. PTFE: SeePolytetrajluoroethylene. PTP: Push-Through Packaging. PU: SeePolyurethanes. Puncture Force: The minimum force required to puncture a flat plastic material, such as film, or textile with a pointed member, such as pyramid, at a slow rate of loading. Puncture Impact: The puncture impact system measures the energy required to break a specimen using a swinging pendulum arm and a round test sample, clamped around its periphery.Puncture Strength: Puncture strength is the force required to penetrate or puncture a specimen with a probe of a specified size and shape. PUR: SeePolyurethanes. PVC: SeePolyvinyl Chloride. Resorcinol Modified Phenolic Resins: Thermosetting polymers of phenol, formaldehyde, and resorcinol; has good heat and creep resistance and dimensional stability. Retort: Laboratory glassware comprisinga sphericalcontainer with a long tube in which substances are distilled, an apparatus for extraction or gasification by heating, or an apparatus for sterilization by heating. PVDC: SeePolyvinylidene Chloride. RH: SeeRelative Humidity. PVDF: SeePolyvinylidene Fluoride. PVF: SeePolyvinyl Fluoride. PVOH: SeePolyvinyl Alcohol. PVT Relationship: Pressure (P), volume (V), and temperature (T) relationship of Boyle’s law stating that the product of the volume of a gas times its pressure is a constant at a given temperature, PV/T=R, where R is Boltzmann constant. R Ra: SeeRoughness Average. Reaction-Injection Molding System: Liquid compositions, mostly polyurethane-based, of thermosetting resins, prepolymers, monomers, or their mixtures. Has good processibility, dimensional stability, and flexibility. Processed by foam molding with in-mold curing at high temperatures. Used in auto parts and office furniture. Also called RIM. Refractive Index: The ratio of the velocity of propagation of an electromagnetic wave in vacuum to its velocity through a specimen. Relative Humidity: The ratio of the actual vapor pressure of the air to the saturation vapor pressure. Also called RH. Relative-Humidity Gradient: The rate of decrease of relative humidity in space at a fixed time, or the magnitude of this decrease. The transmission rate of water vapor through a barrier wall such as plastic film increases with increasing relative humidity gradient, which is a driving force of the process, and, therefore, should be stated for the rate values to be meaningful. Relative Viscosity: The ratio of solution viscosity to the viscosity of the solvent. Resins: SeePolymers. Rigid Thermoplastic Polyurethanes: Rigid thermoplastic polyurethanes are not chemicallycross-linked.Has high abrasion resistance, good retention of properties at low temperatures, but poor heat resistance, weatherability, and resistance to solvents. Rigid thermoplastic polyurethanes are flammable and can release toxic substances. Processed by injection molding and extrusion. Also called Rigid Thermoplastic Urethanes and Nonelastomeric Thermoplastic Polyurethanes. Rigid Thermoplastic Urethanes: SeeRigid Thermoplas- tic Polyurethanes. RIM: SeeReaction Injection Molding System. S SAN: SeeStyrene Acrylonitrile Copolymer. SAN Copolymer: SeeStyrene Acrylonitrile Copolymer. SAN Resin: See Styrene Acrylonitrile Copolymer. SBS: SeeStyrene-Butadiene-Styrene. Seal-Initiation Temperature: The lower limit of a heatseal temperature range at which a thermoplastic material such as film is beginning to fuse and adhere to itself or other thermoplastic materials. Secant Modulus: Secant modulus is the ratio of stress to corresponding strain at a specified strain level. It is usually employed when the stress-strain curve for a material does not exhibit linearity of stress to strain. Service Life: The period of time required for the specified properties of the material to deteriorate under normal use conditions to the minimum allowable level with material retaining its overall usability. Shelf Life: Time during which a physical system, such as a material, retains its storage stability under specified conditions. Also called Storage Life.21 0 Silicone: There are rigid thermoplastic and liquid silicones and silicone rubbers consisting of alternating silicone and oxygen atom chains with organic pendant groups, prepared by hydrolytic polycondensation of chlorosilanes, followedby cross-linking. Silicone rubbers have good adhesion, flexibility, dielectric properties, weatherability, barrier properties, and heat and fire resistance, but decreased strength. Rigid silicones have good flexibility, weatherability, soil repelling properties, and dimensional stability, but poor solvent resistance. Processed by coating, casting, injection compression, and transfer molding. Used in coatings, electronic devices, diaphragms, medical products, adhesives, and sealants. Also called Siloxane. Siloxane: See Silicone. SIS: See Styrene-Isoprene-Styrene. Slip Factor: A property that characterizes the lubricity of a material such as plastic sliding in contact with another material that is reciprocal of the friction coefficient. SMA: See Styrene Maleic Anhydride Copolymer. SMA PBT Alloy: SeeStyrene Maleic Anhydride Copoly- mer PBTAlloy. Softening Point: Temperature at which the material changes from rigid to soft or exhibits a sudden and substantial decrease in hardness. Also called Softening Temperature and Softening Range. Softening Range: See Softening Point. Softening Temperature: See Softening Point. Solubility: A capacity of one substance to be fully dissolved in another without any phase separation, e.g., precipitation. Usually expressed as a percentage of dissolved substance. Solubility Coefficient: The volume of a gas that can be dissolved by a unit volume of solvent at a fixed pressure and temperature. Specific Gravity: The density of a substance relative to the density of water. Spencer Impact: See Impact Resistance, Spencer Impact: Stability: The ability of a physical system, such as a material, to resist a change or degradation under exposure to outside forces, including mechanical force, heat, and weather. See also Degradation. Standard Atmosphere: SeeAtmosphere. Starch: A polysaccharide, consistingof amylose and amylopectin, found in plants such as potatoes. Gels in water. Used in adhesives, textile sizes, and thickeners, and in manufacture of biodegradable polymers such as polyesters. The grades include technical and edible. Starch-Modified, Low Density Polyethylene: Biodegradable thermoplastic starch-grafted low-density polyethylene. Starch-Modified Polypropylene: Biodegradable thermoplastic starch-grafted polypropylene. Starch-Modified Polyurethane: Biodegradable thermoplastic starch-grafted polyurethane. Static Coefficient of Friction: The ratio of the force that is required to start the friction motion of one surface against another to the force, usually gravitational, acting perpendicular to the two surfaces in contact. Also called Coefficient of Friction. Static. Std atm: SeeAtmosphere. Storage Life: See ShelfLife. Storage Stability: The resistance of a physical system, such as a material, to decomposition, deterioration of properties or any type of degradation in storage under specified conditions. STP: Standard temperature and pressure equal to 1atmosphere and O”C, respectively. Used in measurement of permeability coefficient and other properties dependent on temperature and pressure. Styrene Acrylonitrile Copolymer: SAN resins are thermoplastic copolymersof about 70% styrene and 30% acrylonitrile with higher strength, rigidity, and chemical resistance than polystyrene. Characterized by transparency, high heat deflection properties, excellent gloss, hardness, and dimensionalstability.Has low continuous service temperature and impact strength. Processed by injection molding, extrusion, injection-blow-molding, and compression molding. Used in appliances, housewares, instrument lenses for automobiles, medical devices, and electronics. Also called Styrene-Acrylonitrile Copolymer, SAN, SAN Resin, and SAN Copolymer.21 1 Styrene Butadiene Block Copolymer: Thermoplastic amorphous block polymer of butadiene and styrene having good impactstrength, rigidity, gloss, compatibility with other styrenic resins, water resistance, and processibility. Used in food and display containers, toys, and shrink wrap. Styrene Butadiene Copolymer: Thermoplastic polymers of butadiene and >50% styrene having good transparency,
toughness, and processibility. Processed by extrusion, injection and blow-molding, and thermoforming. Used in
film wraps, disposable packaging, medical devices, toys,
display racks, and office supplies.
Styrene Butadiene Styrene: Eachmolecule of SBS polymer consists of block segments of styrene monomer units
and rubber monomer units. Each block segment may consist of 100monomer units or more. The linear A-B-A block
types are styrene butadiene styrene (SBS).
Styrene Isoprene Styrene: Each molecule of SBS polymer consists of block segments of styrene monomer units
and rubber monomer units. Each block segment may consist of 100monomer units or more. The linear A-B-A block
types are styrene isoprene styrene (SIS).
Styrene Maleic Anhydride Copolymer: Thermoplastic
copolymer of styrene with maleic anhydride. Has good
thermal stability and adhesion, but decreased chemical
and light resistance. Processed by injection and foam
molding and extrusion. Used in auto parts, appliances,
door panels, pumps, and business machines. Also called
SMA.
Styrene Maleic Anhydride Copolymer PBT Alloy:
Thermoplastic alloy of styrene maleic anhydride copolymer and polybutylene terephthalate. Has improved
dimensional stabilityand tensile strength. Processed by injection molding.Also called SMA PBT Alloy.
Styrene Plastics: SeeStyrenic Resins.
Styrene Polymers: SeeStyrenic Resins.
Styrene Resins: See Styrenic Resins.
Styrenic Resins: Styrenic resins are thermoplastics prehousehold goods, packaging, films, tools, containers, and
pipes. Also called Styrene Resins, Styrene Polymers, and
Styrene Plastics.
Styrenic Thermoplastic Elastomers: Linear or branched
copolymers containing polystyrene end blocks and elastomer (e.g., isoprene rubber) middle blocks. Has a wide
range of hardnesses, tensile strength, and elongation, and
good low-temperatureflexibility,dielectric properties, and
hydrolytic stability. Processed by injection, blow-molding, and extrusion. Used in coatings, sealants, impact
modifiers, shoe soles, medical devices, tubing, electrical
insulation, and auto parts. Also called TES.
Sulfur Dioxide: A colorless, noncombustible gas or liquid with pungent odor, SO,. Toxic by inhalation, strong
irritant. Derived from pyrites or burning sulfur. Used in
paper pulping, inorganic synthesis, as bleaching agent for
oils, for fumigation, as antioxidant, bactericide, and metal
refining.
Surface Arc Resistance: SeeArc Resistance
Surface Resistivity: Surface Resistivity is the ratio of
the potential gradient parallel to the current along its surface, to the current per unit width of the surface.
Surface Roughness: Relatively fine spaced surface irregularities, the heights, widths, and directions of which
establish the predominant surface pattern.
Surface Tack: Stickiness of a surface of a material such
as wet paint when touched.
Syndiotactic: A polymer molecule in which pendant
groups and atoms attached to the main chain are arranged
in a symmetrical and recurring fashion relative to it in a
single plane.
T
TAB: Tape Automated Bonding.
TAPPI T511: SeeASTMD2176.
TD: Transverse Direction.
pared by free-radical polymerization of styrene alone or
with other unsaturated monomers. The properties of
styrenic resins vary widely with molecular structure, attaining the high performance level of engineering plastics. Processed by blow and injection molding, extrusion,
thermoforming, film techniques, and structural foam moldTear-Propagation Resistance: The force required to
propagate a slit in a flexible plastic film or thin sheeting
at a constant rate of loading, calculated as an average between the initial and the maximumtear-propagationforces.
Also called Tear Resistance, Propagated.
ing. Used heavily forthe manufacture of automotive parts,
Tear Resistance, Initial: SeeInitial Tear Resistance. 212
Tear Resistance, Propagated: See Tear Propagation Re-
sistance.
Tear Strength: The tear strength is a measure of the
resistance of a material to tear forces. The tear strength
of a notched specimen is calculated by dividing the maximum load by the thickness of the specimen.
Tear Strength, Elmendorf Sometimes called the
Elmendorf tear, this tear strength determines the force required to propagate a single-rip tear starting from a cut in
a specimen using a falling-pendulum type (Elmendorf)
apparatus.
Tear Strength, Initial (Graves): Initial Tear Strength
measures the force required to initiate tearing on a specimen.
Tear Strength, Propagating: See Tear Strength,
Elmendorf
Temperature: Property which determines the direction
of heat flow between objects.
Note: The heat flows from the object with higher temperature to that with lower.
Tensile Creep: Tensile Creep is the measurement of the
rate of deformation of a specimen after a certain level of
stress has been applied for a specified amount of time.
Tensile Modulus or Young’s Modulus: Tensile, or
Young’s modulus, is the ratio of stress to strain within the
elastic region of the stress-strain curve (prior to the yield
point).
Tensile Strength: The tensile strength of a material can
be defined as its strength when a pulling force is applied
along the length of a sample.
Tensile Strength at Break: The tensile strength at
break is the force required to break a specimen.
Tensile Yield Strength: Tensileyield strength is the maximum engineering stress,in MPa, at which permanent, nonelastic deformation begins. (IS0 527)
Terephthalate Polyester: Thermoset unsaturated polymer of terephthalic anhydride.
TES: See Styrenic Thermoplastic Elastomers.
Test Methods: Names and designations of material test
methods. Also called Testing Methods.
Test Variables: Terms related to the testing of materials
such as test method names.
Tetrachloroethylene: Other names for tetrachloroethylene include perchloroethylene, PCE, and tetrachloroethene. It is a nonflammable liquid at room temperature. It evaporates easily into the air and has a sharp,
sweet odor. Tetrachloroethylene is widely used for dry
cleaning of fabrics and for metal-degreasing. It is also
used to make other chemicals and is used in some consumer products.
Tetrafluoroethylene Propylene Copolymer: Thermosetting elastomeric polymer of tetrafluoroethylene and propylene. Has good chemical and heat resistance and flexibility. Used in auto parts.
TFE : Tetrafluoroethylene.
Thermal Properties: Properties related to the effects of
heat on physical systems such as materials and heat transport. The effects of heat include the effects on structure,
geometry, performance, aging, stress-strain behavior, etc.
Thermal Stability: The resistance ofaphysical system, such
as amaterial, to decomposition,deterioration of properties
or any type of degradation in storage under specified
conditions.
Thermodynamic Properties: A quantity that is either an
attribute of the entire system or is a function of position,
which is continuous and does not vary rapidly over microscopic distances, except possibility for abrupt changes
at boundaries between phases of the system. Also called
Macroscopic Properties.
Thermoplastic Elastomers: Thermoplastic Elastomers
are a very flexible type of thermoplastic that has the properties of natural rubber. Also called TPE.
Thermoplastic Polyesters: A class ofpolyesters that can
be repeatedly made soft and pliable on heating and hard
(flexible or rigid) on subsequent cooling.
Thermoplastic Polyurethanes: A class of polyurethanes
including rigid and elastomeric polymers that can be
repeatedly made soft and pliable on heating and hard
(flexibleor rigid) on subsequent cooling. Also called Thermoplastic Urethanes, TPUR, and TPU.
Thermoplastic Urethanes: See Thermoplastic Polyure-
thanes. 21 3
Three-Membered Heterocyclic Compounds: A class of
heterocyclic compounds containing rings that consist of
three atoms.
Three-Membered Heterocyclic Oxygen Compounds:
A class of heterocyclic compounds containing rings that
consist of three atoms, one or two of which is an oxygen.
Time: SeeProcessing Time.
Total Energy Dart Drop: SeeImpact Resistance, Dart
Drop
Toughness: Property of a material indicating its ability
to absorb energy by plastic deformation rather than crack
or fracture.
TPE: See Thermoplastic Elastomers.
TPO: See OleJinic Thermoplastic Elastomers.
TPU: See Thermoplastic Polyurethanes.
TPUR: See Thermoplastic Polyurethanes.
Transition Point: SeePhase Transition Point.
Transition Temperature: SeePhase Transition Point.
Transmittance: Often recorded as percent, transmittance
represents the fraction of radiant energy that passes
through the sample.
Tribasic Lead Maleate: A salt of maleic acid, highly effective as heat stabilizer for polymeric materials. Limited
to use in applications where toxicity and lack of clarity
can be tolerated.
Turbidity: The cloudiness in a liquid caused by a suspension of colloidal liquid droplets, or fine solids.
TSCA: Toxic Substance Control Act.
U
UHMWPE: See Ultrahigh Molecular- Weight Polyeth-
ylene.
ULDPE: Ultra Low Density Polyethylene.
UL Underwriters Laboratories Inc.: UL is an independent, not-for-profit product safety testing and certification organization.
UL 746B: Polymeric Materials – Long Term Property
Evaluation is a method for the evaluation of physical,
electrical, flammability, thermal, and other properties of
the materials under consideration and are intended to provide guidance for the material manufacturer, the molder,
the end-product manufacturer, safety engineers, and other
interested parties.
Ultimate Elongation: Ultimate Elongation is the percentage elongation of a specimen at rupture under tensile
loading.
Ultimate Hot-Tack Strength: SeeHot-Tack Strength.
Ultimate Seal Strength: Maximum force that a heatsealed thermoplastic film can sustain in a tensile test without seal failure per unit length of the seal.
Ultimate Tensile Strength: Ultimate tensile strengthisthe
maximum stress a material can withstand before failing,
whichever occurs at the higher stress level.
Ultrahigh Molecular-Weight Polyethylene: Thermoplastic linear polymer of ethylene with molecular weight
in the millions. Has good wear and chemical resistance,
toughness, and antifriction properties, but poor
processibility. Processed by compression molding and ram
extrusion. Used in bearings, gears, and sliding surfaces.
Also called UHMWPE.
Uniaxially Oriented: A state of material such as polymeric film or composite characterized by the permanent orientation of its components such as polymer molecules or reinforcing fibers in one direction. The orientation is achieved by a number of different processes, e.g.,
stretching, and is intended to improvethe mechanicalproperties of the material.
Units: See Units of Measurement.
Units of Measurement: Systematic and nonsystematic
units for measuring physical quantities, including metric
and US pound-inch systems. Also called Units.
Urea Resins: Thermosetting polymers of formaldehyde
and urea. Has good clarity, colorability, scratch, fire,
and solvent resistance, rigidity, dielectric properties,
and tensile strength, but decreased impact strength
and chemical, heat, and moisture resistance. Must
be filled for molding. Processed by compression and
injection molding, impregnation, and coating. Used
in cosmetic containers, housings, tableware, electrical insulators, countertop laminates, adhesives, and
coatings.214
Urethane Polymers: SeePolyurethanes
Urethane Resins: See Polyurethanes.
Urethane Thermoplastic Elastomers: Block polyether
or polyester polyurethanes containing soft and hard segments. Has good tensile strength, elongation, adhesion,
and a broad hardness and service temperature ranges, but
decreased moisture resistance andprocessibility. Processed
by extrusion, injection molding, film blowing, and coating.
Used intubing, packaging film,adhesives, medical devices,
conveyor belts, auto parts, and cable jackets. Also called
TPU.
Urethanes: SeePolyurethanes.
V
VDC: Vinylidene Chloride.
Veneer: In rubber industry, a thin film applied on a rubber article to protect it against oxygen and ozone attack,
acts as a migration barrier or for decorative purposes.
Vicat Softening Point: The temperature at which a flatended needle of prescribed geometry will penetrate a
thermoplastic specimen to a certain depth under a specified load using a uniform rate of temperature rise.
Note: Vicat softening point is determined according to
ASTM D1525 test for thermoplastics such as polyethylene
which has no definite melting point. Also called Vicat
Softening Temperature.
Vicat Softening Temperature: See Mcat Softening Point.
Vinyl Ester Resins: Thermosetting acrylated epoxy resins containing styrene reactive diluent. Curedby catalyzed
polymerization of vinyl groups and cross-linking of hydroxy groups at room or elevated temperatures. Has good
chemical, solvent, and heat resistance, toughness, and flexibility, but shrinks during cure. Processed by filament
winding, transfer molding, pultrusion, coating, and lamination. Used in structural composites, coatings, sheet
molding compounds, and chemical apparatus.
Vinyl Resins: Thermoplastics polymer of vinyl compounds such as vinyl chloride or vinyl acetate. Have
good weatherability, barrier properties, and flexibility,
but decreased solvent and heat resistance. Processed by
molding, extrusion, and coating. Used in films and packaging.
Vinyl Thermoplastic Elastomers: Vinylresin alloys having good fire and aging resistance, flexibility, dielectric
properties, and toughness. Processed by extrusion. Used
in cable jackets and wire insulation.
Vinylidene Fluoride Hexafluoropropylene Copolymer:
Thermoplastic polymer of vinylidene fluoride and
hexafluoropropylene. Has good antistick, dielectric, and
antifriction properties, and chemical and heat resistance,
but decreased mechanical strength, creep resistance, and
poor processibility. Processed by molding, extrusion, and
coating. Used in chemical apparatus, containers, films,
and coatings.
Vinylidene Fluoride Hexafluoropropylene Tetrafluoro-
ethylene Terpolymer: Thermosetting elastomeric polymer of vinylidene fluoride, hexafluoropropylene, and
tetrafluoroethylene. Has good chemical and heat resistance and flexibility. Used in auto parts.
VLDPE: Very Low Density Polyethylene.
Volume Resistivity: Volume Resistivity is the resistance
in ohms between opposite faces of a centimeter cube of
the material tested.
Vulcanizate: Rubber that had been irreversibly transformed fiom predominantly plastic to predominantly elastic material by vulcanization (chemical curing or crosslinking) using heat, vulcanization agents, accelerants, etc.
Vulcanizate Cross-links: Chemical bonds formed between polymeric chains in rubber as a result of vulcanization.
W
Warpage: See Warping.
Warping: Dimensional distortion or deviation from the
intended shape of a plastic or rubber article as a result of
nonuniform internal stress, e.g., caused by uneven heat
shrinkage. Also called Warpage.
Water Swell: Expansion of material volume as a result
of water absorption.
Water-Vapor Transmission Rate: A measure of water
vapor (moisture) permeability of a barrier wall such as
plastic film. Vapor transmission rate, VTR, is a coefficient in modified Fick’s first law that states that the21 5
weight (W) of a vapor that penetrates a barrier wall is
directly proportional to the area (A) of the wall and time
(t), and is inversely proportional to the wall thickness (s);
or W = VTR . (A . t)/s. The water vapor transmission rate
is a characteristic constant for the wall material that is
homogeneous in the direction of penetration. It depends
on the temperature and relative humidity gradient. Also
called WVTR.
Wettability: The degree or extent to which something
absorbs or can be made to absorb moisture.
Whiting: A finely divided form of calcium carbonate
(CaCO,) obtained by milling high-calcium limestone,
marble, shell, or chemically precipitated calcium carbonate. Used as an extender filler in plastics and rubbers.
WVTR: See Water-Vapor Transmission Rate.
X
Xylene: An aromatic hydrocarbon comprising benzene
ring containing two methyl substituent groups, C,H,Me,.
It is a colorless, flammable, toxic liquid usually consisting of a mixture of three isomers: ortho-, meta-, and
para-xylene. Derived from coal tar and petroleum. Used
in aviation fuel, solvent for alkyd resins and coatings,
and in the synthesis of phthalic acids.
Y
Yield Point: Yield point is the first point (load) at which
the specimen yields, where the specimen’s cross-sectional
area begins to decrease (neckdown) significantly, or an
increase in strain occurs without an increase in stress.
Yield Strength: The stress at which an elastic material
under increasing stress ceases to behave elastically. Under conditions of tensile stress, the elongation is greater
than the increase in stress.
Young’s Modulus: See Tensile Modulus This page intentionally left blankTrade Names
Basell Polyolefins
Adflex . 167. 168
Polybutene-1 . 145. 147
BASF
UltramidA5 . 51. 53
BP Chemicals
Barex . 9. 10. 11
Dow Chemical Company

كلمة سر فك الضغط : books-world.net
The Unzip Password : books-world.net