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Definitions of Plastic Resins
Acetal
An engineering thermoplastic produced by the polymerization of
purified formaldehyde [CH2O] into both homopolymer and copolymer
types. Typical applications are found in consumer products, automotive
parts, and industrial machinery parts.
Acrylics
A family of thermoplastic resins of acrylic esters [CH2CHCOOR]
or methacrylic esters [CH2C(CH3)COOR]. The acrylates may be methyl,
ethyl, butyl, or 2-ethylhexyl. Usual methacrylates are the methyl,
ethyl, butyl, laural and stearyl. Typical applications are found
in lighting fixtures, glazing and automotive parts.
Acrylonitrile-Butadiene-Styrene (ABS)
A class of thermoplastic terpolymers including a range of resins,
all prepared with usually more than 50% styrene [C6H5CHCH2] and
varying amounts of acrylonitrile [CH2CHCN] and butadiene [CH2CHCHCH2].
The three components are combined by a variety of methods involving
polymerization, graft copolymerization, physical mixtures and
combinations thereof. Typical applications are found in appliances,
automotive parts, pipe, business machine and telephone components.
Alkyds
Thermosetting unsaturated polyester resins produced by reacting
an organic alcohol with an organic acid, dissolved in and reacted
with unsaturated monomers such as styrene [C6H5CHCH2], diallyl
phthalate [C6H4(COOCH2CHCH2)2], diacetone acrylamide [CH3COCH2C(CH3)2CHCHCONH2]
or vinyl toluene [CH2CHC6H4CH2]. Typical applications are found
in electrical uses, automotive parts, and as coatings.
Cellulosics
A family of thermoplastic resins manufactured by chemical modification
of cellulose [(C6H10O5)n]. Included are: cellophane—regenerated
cellulose made by mixing cellulose xanthate [ROCSSH] with a dilute
sodium hydroxide [NaOH] solution to form a viscose, then extruding
the viscose into an acid bath for regeneration; cellulose acetate—an
acetic acid ester [CH3COOC2H5] of cellulose; cellulose acetate
butyrate—a mixed ester produced by treating fibrous cellulose
with butyric acid [CH3CH2CH2COOH], butyric anhydride [(CH3CH2CH2CO)2O],
acetic acid [CH3COOH] and acetic anhydride [(CH3CO)2O] in the
presence of sulfuric acid [H2SO4]; cellulose propionate—
formed by treating fibrous cellulose with propionic acid [CH3CH2CO2H]
and acetic acid and anhydrides in the presence of sulfuric acid;
cellulose nitrate—made by treating fibrous cellulosic materials
with a mixture of nitric [HNO3] and sulfuric acids. Typical applications
are found in packaging, consumer products, and automotive parts.
Coumarone-Indene
Thermoplastic resin obtained by heating mixtures of coumarone
[C8H6O] and indene [C6H4CH2CHCH] with sulfuric acid [H2SO4] to
promote polymerization. These resins have no commercial applications
when used alone. They are used primarily as processing aids, extenders
and plasticizers with other resins in asphalt floor tile.
Diallyl Phthalate (DAP)
The term DAP is used both for the monomeric and polymeric forms.
The monomer [C6H4(COOCH2CHCH2)2] is used as a cross-linking agent
in unsaturated polyester resins. As a polymer, it is used in the
production of thermosetting molding powders, casting resins and
laminates.
Epoxy
Thermosetting resins that, in the uncured form, contain one or
more reactive epoxide or oxirane groups. These epoxide groups
serve as cross-linking points in the subsequent curing step, in
which the uncured epoxy is reacted with a curing agent or hardener.
Cross-linking is accomplished through the epoxide groups as well
as through hydroxyl groups that may be present. Most conventional
unmodified epoxy resins are produced from epichlorohydrin (chloropropylene
oxide) [CH2OCHCH2Cl] and bisphenol A [(CH3)2C(C6H4OH)2]. The other
types of epoxy resins are phenoxy resins, novolac resins, and
cycloaliphatic resins. Epoxy resins are used as protective coatings,
bonding adhesives, in building and construction, and for electrical
, and many other uses.
Fluoropolymer
A family of thermoplastic resins analogous to polyethylene in
which some of the hydrogen atoms attached to the carbon chain
are replaced by fluorine or fluorinated alkyl groups. In some
cases, other halogens such as chlorine are also part of the molecule.
The most common commercial fluoropolymers are: FEP (fluorinated
ethylene-propylene) from tetrafluoroethylene [C2F4] and hexa-fluoropropylene
[C3F6]; PTFE (polytetra fluoroethylene) from the polymerization
of tetrafluoroethylene and ethylene [C2H4]; PFA (perfluoroalkoxy)
from tetrafluoroethylene and perfluoropropyl vinyl ether [C3H7C4OF5];
PCTFE (polychlorotrifluoro-ethylene) from chlorotrifluoro-ethylene
monomer [C2F3CI]; CTFE-VDF (polychlorotrifluoroethylenevinylidene
fluoride) from chlorotrifluoroethylene and vinylidene fluoride
[C2H2F2]; E-CTFE (polyethylenechlorotrifluoroethylene) from chlorotrifluoroethylene
and ethylene; PVDF (polyvinylidene fluoride) from vinylidene fluoride
monomer; and PVF (polyvinyl fluoride) from vinyl fluoride monomer
[C2H3F]. Typical applications for fluoropolymers are found in
electrical/ electronic uses and pipe and chemical processing equipment.
Melamine-Formaldehyde
Thermosetting resins formed by the condensation reaction of formaldehyde
[HCHO] and melamine [C3N3(NH2)3]. The chemistry is analogous to
that of ureaformaldehyde except that the three amino groups of
melamine provide more possibilities for cross-linking, are more
highly reactive, and all six hydrogen atoms of melamine will react,
forming the hexamethyl compound. Typical applications are found
in bonding and adhesives, coatings, and consumer products.
Nitrile Resins
Thermoplastic resins composed of acrylonitrile [CH2CHCN] along
with comonomer such as acrylates, methacrylates, butadiene [CH2CHCHCH2]
and styrene [C6H5CHCH2]. Both straight copolymers and copolymers
grafted onto elastomeric backbones are available. The unique property
of these materials is outstanding resistance to passage of gases
and water vapor, making them useful in packaging applications.
Nylon
A generic name for a family of long-chain polyamide engineering
thermoplastics which have recurring amide groups [-CO-NH-] as
an integral part of the main polymer chain. Nylons are synthesized
from intermediates such as dicarboxylicacids, diamines, amino
acids and lactams, and are identified by numbers denoting the
number of carbon atoms in the polymer chain derived from specific
constituents, those from the diamine being given first. The second
number, if used, denotes the number of carbon atoms derived from
a diacid. Commercial nylons are as follows: nylon 4 (polypyrrolidone)-a
polymer of 2-pyrrolidone [CH2CH2CH2C(O)NH]; nylon 6 (polycaprolactam)-made
by the polycondensation of caprolactam [CH2(CH2)4NHCO]; nylon
6/6-made by condensing hexamethylenediamine [H2N(CH2)6NH2] with
adipic acid [COOH(CH2)4COOH]; nylon 6/10-made by condensing hexamethylenediamine
with sebacic acid[COOH(CH2)8COOH]; nylon 6/12-made from hexamethylenediamine
and a 12-carbon dibasic acid; nylon 11-produced by polycondensation
of the monomer 11-amino-undecanoic acid [NH2CH2(CH2)9COOH]; nylon
12-made by the polymerization of laurolactam [CH2(CH2]10CO)or
cyclododecalactam, with 11 methylene units between the linking
-NH-CO- groups in the polymer chain. Typical applications for
nylons are found in automotive parts, electrical/electronic uses,
and packaging.
Petroleum Resins
Thermoplastic resins obtained from a variable mixture unsaturated
monomers recovered as byproduct from cracked and distilled petroleum
streams. They also contain indene [C6H4CH2CHCH], which is copolymerized
with a variety of other monomers including styrene [C6H5CHCH2],
vinyl toluene [CH2CHC6H4CH3], and methyl indene [C6H3CH3CH2CHCH].
Typical applications are found in adhesives, printing inks, rubber
compounding, and surface coatings.
Phenolic
These thermosetting resins are credited with being the first commercialized
wholly synthetic polymer or plastic. The basic raw materials are
formaldehyde [HCHO] and phenol [C6H5OH], although almost any reactive
phenol or aldehyde can be used. The phenols used commercially
are phenol, cresols [CH3C6H4OH], xylenols [(CH3)2C6H3OH], p-t-butylphenol
[C4H9C6H4OH], p-phenylphenol [C6H5C6H4OH], bisphenols [(C6H4OH)2],
and resorcinol [C6H4(OH)2]. The aldehydes used are formaldehyde
and furfural [C4H3OCHO]. In the uncured and semi- cured condition,
phenolic resins are used as adhesives, casting resins, potting
compounds, and laminating resins. As molding powders, phenolic
resins can found in electrical uses.
Polyamide-Imide
Engineering thermoplastic resins produced by the condensation
reaction of trimellitic anhydride [OCC6H2C2O3] and various aromatic
diamines. Typical applications are found in aerospace, automotive
and heavy equipment industries.
Polyarylates
Engineering thermoplastic resins produced by interfacial polymerization
of an aqueous solution of the disodium salt of bisphenol A [(CH3)2C(C6H4OH)2]
with phthalic acid chlorides [C6H4(CO)2Cl2] in methylene chloride
(CH2Cl2]. The major use of polyarylates is in outdoor lighting.
Polybutylene
Thermoplastic resins produced via stereospecific Ziegler-Natta
polymerization of butene-1 monomer [CH2CHCH2CH3]. Typical applications
are found in pipe and packaging film.
Polycarbonate
Engineering thermoplastic resins produced by (1) phosgenation
of dihydric phenols, usually bisphenol A [(CH3)2C(C6H4OH)2], (2)
ester exchange between diaryl carbonates and dihydric phenols,
usually between diphenyl carbonate [(C6H5O)2CO] and bisphenol
A and (3) interfacial polycondensation of bisphenol A and phosgene[COCl2].
Typical applications are found in glazing, appliances, and electrical
uses.
Polyethylene
A family of thermoplastic resins obtained by polymerizing the
gas ethylene [C2H4]. Low molecular weight polymers of ethylene
are fluids used as lubricants; medium weight polymers are waxes
miscible with paraffin; and the high molecular weight polymers
(i.e., over 6000) are the materials used in the plastics industry.
Polymers with densities ranging from about .910 to .925 are called
low density; those of densities from .926 to .940 are called medium
density; and those from .941 to .965 and over are called high
density. The low density types are polymerized at very high pressures
and temperatures, and the high density types at relatively low
temperatures and pressures. A relatively new type called linear
low density polyethylene is manufactured through a variety of
processes: gas phase, solution, slurry, or high pressure conversion.
A high efficiency catalyst system aids in the polymerization of
ethylene and allows for lower temperatures and pressures than
those required in making conventional low density polyethylene.
Copolymers of ethylene with vinyl acetate, ethyl acrylate, and
acrylic acid are commercially important. Major polyethylene applications
can be found in packaging, housewares, toys and communications
equipment.
Polyimides
A family of thermoset and thermoplastic resins characterized by
repeating imide linkages: There are four types of aromatic polyimides:
(1) condensation products made by the reaction pyromellitic dianhydride
(PMDA) [C6H2(C2O3)2] and aromatic diamines such as 4,4'-diaminodiphenyl
ether [(C6H4NH2)2O]; (2) condensation products of 3,4,3',4'-benzophenone
tetracarboxylic dianhydride (BTDA) [(C6H5)2CO(C2O3)2] and aromatic
amines;(3) the reaction of BTDA and a diisocyanate such as 4,4'-methylene-bis(phenylisocyanate)
[OCNC6H4CH2C6H4NCO]; and (4) a polyimide based on diaminophenylindane
and a dicarboxylic anhydride such as carbonyldiphthalic anhydride
[OC6H4(CO)2COC6H4(CO)2]. Thermoset polyimides are produced in
condensation polymers that possess reactive terminal groups capable
of subsequent cross-linking through an addition reaction. Typical
applications for thermoplastic and thermosetting polyimides are
transportation and electronics.
Polyphenylene Oxide, Modified
Engineering thermoplastic resins produced by the oxidative coupling
of 2, 6-dimethylphenol [(CH3)2C6H3OH] (xylenol), then blended
with impact polystyrene. Typical applications are found in electrical/electronic
uses, business machine parts, appliances, and automotive parts.
Polyphenylene Sulfide
Engineering thermoplastic resins produced by the reaction of p-dichlorobenzene
[C6H4CI2] with sodium sulfide [Na2S]. The major use for polyphenylene
sulfide is in electrical/ electronic parts and automotive parts.
Polypropylene
Thermoplastic resins made by polymerizing propylene [CH3CHCH2]
and in the case of copolymers with monomers, with suitable catalysts,
generally aluminum alkyl and titanium tetrachloride mixed with
solvents. The monomer unit in polypropylene is asymmetric and
can assume two regular geometric arrangements: isotactic, with
all methyl groups aligned on the same side of the chain, or syndiotactic,
with the methyl groups alternating. All other forms, where this
positioning is random, are called atactic. Commercial polypropylene
contains 90-97% crystalline or isotactic PP with the remainder
being atactic. Most processes remove excess atactic PP. This by-product
is used in adhesives, caulks, and cablefilling compounds. Major
applications of commercial PP are found in packaging, automotive,
appliance and carpeting markets.
Polystyrene
High molecular weight thermoplastic resins produced generally
by the free-radical polymerization of styrene monomer [C6H5CHCH2]
which can be initiated by heating alone but more effectively by
heating in the presence of free-radical initiator (such as benzoyl
peroxide [(C6H5CO)2O2]. Typical processing techniques are modified
mass polymerization or solution polymerization, suspension polymerization,
and expandable beads. Major markets for polystyrene are in consumer
and institutional products, electrical/electronic uses, and building/
construction.
Polyurethanes
A large family of polymers based on the reaction product of an
organic isocyanate with compounds containing a hydroxyl group.
The commonly used isocyanates are toluene diisocyanate (TDI) [CH3C6H3(NCO)2],
methylene diphenyl isocyanate (MDI) [OCNC6H4CH2C6H4NCO], and polymeric
isocyanates (PMDI), obtained by the phosgenation of polyamines
derived from the condensation of aniline [C6H5NH2] with formaldehyde
(HCHO]. Polyols (with hydroxyl groups) are macroglycols which
are either polyester or polyether based. Polyurethane elastomers
and resins take the form of liquid castings systems thermoplastic
elastomers and resins, microcellular products, and millible gums.
Typical applications are found in the automotive industry. Polyurethane
foams are widely used in transportation, furniture, and construction
markets.
Polyvinyl Acetate (PVAc) & Other Vinyls
Polyvinyl acetate is a thermoplastic resin produced by the polymerization
of vinyl acetate monomer [CH3COOCHCH2] in water producing an emulsion
with a solids content of 50-55%. Most polyvinyl acetate emulsions
contain co-monomers such as n-butyl acrylate, 2-ethyl hexyl acrylate,
ethylene, dibutyl maleate and dibutyl fumarate. Polymerization
of vinyl acetate with ethylene also can be used to produce solid
vinyl acetate/ethylene copolymers with more than 50% vinyl acetate
content. Polyvinyl alcohol (PVOH) is produced by methanolysis
or hydrolysis of polyvinyl acetates. The reaction can be controlled
to produce any degree of replacement of acetate groups. Co-polymers
of replaced acetate groupings and other monomers such as ethylene
and acrylate esters are commercially important. Polyvinyl butyral
(PVB) is made by reacting PVOH with butyraldehyde [CH3(CH2)2CHO].
Polyvinyl formal is made by condensing formaldehyde [HCHO] in
presence of PVOH or by the simultaneous hydrolysis and acetylization
of PVAc. Polyvinylidene chloride is made by the polymerization
of 1,1-dichloroethylene [CH2CCL2]. Typical applications for the
above resins are found in adhesives, paints, coatings and finishes,
and packaging.
Polyvinyl Chloride
Thermoplastic resins produced by the polymerization of the gas
vinyl chloride [CH2CHCl]. Under pressure, vinyl chloride becomes
liquefied and is polymerized by one of four basic processes: suspension,
emulsion, bulk, or solution polymerization. The pure polymer is
hard, brittle and difficult to process, but it becomes flexible
when plasticizers are added. A special class of PVC resin of fine
particle size, often called dispersion grade resin, can be dispersed
in liquid plasticizers to form plastisols. The addition of a volatile
diluent or a solvent to the plastisol produces an organosol. Copolymers
with vinyl acetate, vinylidene chloride, and maleate and fumarate
esters find commercial application. Major markets for PVC are
in building/construction, packaging, consumer and institutional
products, and electrical/electronic uses.
Styrene Acrylonitrile
Thermoplastic copolymers of styrene [C6H5CHCH2] and acrylonitrile
[CH2CHCN]. SAN resins are random, amorphous copolymers produced
by emulsion, suspension, or continuous mass polymerization. Typical
uses include automobile instrument lenses and housewares.
Styrene Butadiene Latexes & Other Styrene Copolymers
Styrene butadiene latexes usually have a resin content of about
50%. The styrene/butadiene ratio varies from 54:46 to 80:20. Most
are carboxylated by the use of such acids as maleic [HOOCCHCHCOO],
fumaric [HOOCCHCHCOOH], acrylic [CH2CHCOOH], or methacrylic [CH2C(CH3)COOH].
Two types of styrene-maleic anhydride (SMA) [(COCH)2O] are available:
SMA copolymers, with and without rubber impact modifier (e.g.,
DYLARK¨) and SMA terpolymer alloys (e.g., CADON¨). K-Resin¨
is a solid styrenebutadiene copolymer resin. Acrylic monomers
are also used in conjunction with styrene (or styrene plus other
monomers) to produce specialty resins. For example, there are
transparent terpolymers of methyl methacrylate, butadiene, and
styrene (MBS), and others of acrylonitrile, an acrylic monomer,
and styrene (AAS). Ion-exchange resins or divinylbenzene-modified
polystyrene are another variation. SB latexes are used in carpet
backing and paper coatings. The other styrenics are used in paints,
coatings, and floor polishes, plus many other uses.
Sulfone Polymers
A family of engineering thermoplastic resins characterized by
the sulfone [SO2] group. Polysulfone is made by the reaction of
the disodium salt of bisphenol A[(CH3)2C(C6H4OH)2] with 4,4'-
dichlorodiphenyl sulfone 4,4'-DCDPS [(C6H4Cl)2SO2]. Polyethersulfone
is made by the reaction of 4,4'-DCDPS with potassium hydroxide
[KOH]. Polyphenylsulfone is similar to the other sulfone polymers.
Typical applications for sulfone polymers are found in electrical/electronic
uses and automotive parts.
Thermoplastic Polyester (Saturated)
A family of polyesters in which the polyester backbones are saturated
and hence unreactive. The most common commercial types are: PET
(polyethylene terephthalate) produced by polycondensation of ethylene
glycol [CH2OHCH2OH] with either dimethyl terephthalate (DMT) [C6H4(COOCH3)2]
or terephthalic acid (TPA) [C6H4(COOH)2]; and PBT (polybutylene
terephthalate) produced by the reaction of DMT with 1,4 butanediol
[HO(CH2)4OH]. Typical applications are found in packaging, automotive,
electrical, and consumer markets.
Unsaturated Polyester
Thermosetting resins made by the condensation reaction between
difunctional acids and glycols. The resulting polymer is then
dissolved in styrene [C6H5CHCH2] or other vinyl unsaturated monomer.
The structures of the acids and glycols used and their proportions,
especially the ratio of the unsaturated versus the saturated acid,
and the type and amount of monomer used, are all tailored for
each resin to balance economy, processing characteristics, and
performance properties. One common formulation is the reaction
of maleic anhydride [(COCH)2O], phthalic anhydride [C6H4(CO)2O],
and propylene glycol [CH3CHOHCH2OH]. Both dicyclopentadiene [C10H12]
and isophthalic acid [C6H4(COOH)2] can be substituted for phthalic
anhydride. Vinyl ester resins are linear reaction products of
bisphenol A [(CH3)2C(C6H4OH)2] and epichlorohydrin [CH2OCHCH2Cl]
that are terminated with an unsaturated acid such as methacrylic
acid [CH2C(CH3)COOH]. Typical applications are found in transportation,
appliances, electrical, and construction markets.
Urea-Formaldehyde
Formed by the condensation reaction of formaldehyde [HCHO] and
urea [CO(NH2)2]. These thermoset resins are clear water-white
syrups or white powered materials which can be dispersed in water
to form colorless syrups. They cure at elevated temperatures with
appropriate catalysts. Molding powders are made by adding fillers
to the uncured syrups, forming a consistency suitable for compression
and transfer molding. The liquid and dried resins find extensive
uses in laminates and chemically resistant coatings. The molding
compounds are formed into rigid electrical and decorative products.
Sources: Chemical Economics Handbook, SRI International, Modern
Plastics Encyclopedia, Whittington's Dictionary of Plastics, The
Condensed Chemical Dictionary
society of plastics http://www.socplas.org/industry/defs.htm 8mar01
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