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 dicarboxylic
acids, 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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