School Science Lessons
Appendix D, Polymers and plastics
2012-05-17 SP
Please send comments to: J.Elfick@uq.edu.au
Table of contents
1.0.0 Polymers and plastics
Breakdown polymers using heat: 3.97
Breakdown polymers into small molecules: 3.4.4.0
List of polymers, plastics, and synthetic fibres: 2.0.0
Plastics recycling code: 3.5.3
Plastics manufacture: 9.0
Polymer foam: 3.5.1
Polymer terminology: 3.6.0
Polymers (definitions) 3.0.1
Polymers, Identification tests for polymers: 3.103
Polymers and plastics (experiments): 3.4.0
Polymerization polymer: 3.6.9
Polymerization reaction: 16.2.4.2.1
Polymorphism polymer: 3.6.10
Polypeptides, amino acids: 16.3.6.0.0
Tests for plastics in known density solutions: 3.104
Tests for plastics, natural fibres and synthetic fibres: 3.102
Tests for polymers: 3.103
Tests for synthetic fibres: 4.3
Thermoplastic polymers: 3.0.2
Thermosetting polymers: 3.0.3
2.0.0 List of polymers, plastics, and synthetic fibres
("Poly-" is the prefix denoting a polymer)
ABS, acrylonitrile, butadiene and styrene, thermoset plastics: 3.7.5.1
Acetals, (alcohol + aldehyde), RCH(OR')2: 16.1.3.8
Acetate polymer, Generic name for fibres from cellulose acetate, CA: 3.5.8
Acrilan polymer, synthetic fibre, polyacrylic, Trade name for fibres from polyacrylonitrile: 3.7.5
Acryl polymer, Generic name for fibres >85% acrylonitrile units
Acrylic acid, propenoic acid, CH2CHCOOH, synthetic fibre, acrylic resins, "acrylics": 3.4.2.8.1
Acrylic resin, Polymethyl methacrylate, PMMA: 3.7.24
Acrylonitrile rubber
Addition polymers: 3.4.2
Alcantara polymer, Synthetic suede from polyester fibres in a polyurethane matrix
Alginate polymer: 3.4.12
Alkyd resin: 16.11.1
Amino-plastics, amino resins, urea-formaldehyde (UF), melamine-formaldehyde (MF): 3.8.5
Aniline-formaldehyde, thermoset plastics: 3.8.6
Araldite polymer, Epoxy resins: 3.8.7
Aramid synthetic fibre, Nomex, Kevlar, Twaron: 3.7.6.1.1
Aramide polymer, Generic name for fibres from aromatic polyamides: 3.7.6
Arcopal crockery: 3.8.13
Art silk
Azlon synthetic fibre
Bakelite polymer, Thermoset from phenol and formaldehyde: 3.8.10
Balata polymer, Natural trans-1,4-polyisoprene: 3.7.22
Bamboo fibre
Ban-lon synthetic fibre
British Celanese
Brominated Flame Retardants, (BFRs): 3.0.5
Carbon fibre, synthetic fibre, CarbonCast
Casein, milk casein, (artificial horn), thermoset plastics: 3.5.6
Cellophane polymer, Films from regenerated cellulose: 3.5.7
Celluloid, cellulose nitrate, cellulose acetate, thermoset plastics: 3.5.7
Cellulose acetate, CA, acetate, cellulose fibre, artificial fibre, Cellulose acetate butyrate, CAB: 3.5.8
Cellulose nitrate, nitrocellulose, flash paper: 3.5.9
Cellulose triacetate: 3.5.8
Chemical sources of polymer materials: 3.4.02
Collodion 3.5.10
Condensation polymers: 3.4.3.0
Conex synthetic fibre
Codura synthetic fibre
Courtelle, polyacrylic fibre
Darlexx synthetic fibre
Density of polymers: 3.6.1
Derclon synthetic fibre
Diolen polymer, Fibres from polyethylene terephthalate: 3.7.19
Dralon polymer, Fibres from polyacrylonitrile
Dyneema synthetic fibre, Spectra synthetic fibre
Dynel synthetic fibre
Elasterell synthetic fibre
Elastomer polymer: 3.6.2
Electrostatic series, triboelectric series: 31.1.02
Epoxy compounds, (O atoms in CCO ring), Epoxy resin polymers, thermoset plastics: 3.4.3.1
Epoxy resin polymers, thermoset plastics: 3.4.3.1
Ethylene vinyl acetate, (EVA) used in sports shoes
Fibres, Tests for plastics, natural fibres and synthetic fibres: 3.102
Fibreglass synthetic fibre, glass fibre
Glass transition temperature (Tg): 3.4.01
Glycerol-phthalic anhydrides, thermoset plastics: 3.8.8
Grilen polymer, Fibre from polyethylene terephthalate: 3.7.19
Gutta percha polymer, natural polymer, mainly trans-1.4-polyisoprene (latex of
Palaquium oblongifolium)
Gold Flex
Hair, Fibrous proteins and globular proteins: 16.3.6.0.2
Hostalen polymer, Polyethylene thermoplastic
Hostalen PP polymer, Polypropylene thermoplastic
Hostalit polymer, Polyvinyl chloride, thermoplastic
Hostaphan polymer, Films from polyethylene terephthalate: 3.7.19
Igelit polymer, Polyvinyl chloride, thermoplastic
Imides, imido group: (-CONHCO-), (R1CO-NH-COR2): 16.1.5.8
Ingeo synthetic fibre
Initiator polymer: 3.6.3
Innegra S synthetic fibre
Isomerization polymer: 3.6.4
Kevlar, Kevlar KM2, synthetic fibre, polyamide: 3.7.6
Lastol synthetic fibre
Lupolen polymer, Polyethylene thermoplastic
Luran polymer, Thermoplastic from styrene and acrylonitrile
Lyocell cellulose fibre
M5 synthetic fibre
Marlex polymer, Thermoplastic polyethylene
Melamine-formaldehyde resins, Formica, Bakelite, thermoset plastics: 16.2.4.2.1
Metallic fibre
Modacrylic synthetic fibre
Modal textile cellulose fibre
Moltopren polymer, Cellular polymer from polyurethanes
Monomer polymer: 3.6.5
Mylar polymer, Polyethylene terephthalate, PET, thermoplastic: 3.7.19
Natural polymers: 3.4.1.0
Natural rubber polymer, cis-1.4-polyisoprene (latex of Hevea brasiliensis)
Nomex synthetic fibre, polyamide: 3.7.6
Nylon polymer, synthetic fibre, polyamide, Nylon 6, Nylon 6-6: 3.7.6
Neoprene polymer, polychloroprene: 3.7.12
Nitrocellulose
Nylon: 3.7.6.1
Olefin synthetic fibre, polyolefin fibre, that are long-chain polymers of ethylene or propylene,
i.e. polyethylene (polypropylene, PP)
Orlon polymer, orlon synthetic fibre, polyacrylic, Fibre from polyacrylonitrile: 3.7.5
Perlon polymer, Fibre from polycaprolactam: 3.7.6.1
Phthalates: 3.0.4
Phenols, group: (OH-C), in a benzene ring, Phenol = (C6H5O6): 16.1.3.2
Phenolics, phenol resins, phenol-formaldehyde resins: 3.8.10
PLA synthetic fibre, polylactic acid, polylactide
PLGA synthetic fibre
Plasticizers polymer: 3.6.7
Plastics
Plastics, and synthetic fibres, 2.0.0
Plastics, Identification tests for plastics: 3.102
Plastics manufacture, 9.0
Plastics recycling code: 3.5.3
Polymer density: 3.6.1
Polymers: 3.0.1
Polymers and plastics (experiments): 3.4.0
Polymers, Thermoplastic polymers: 3.0.2
Polymers, Thermosetting polymers: 3.0.3
Plexiglas polymer, Thermoplastic, polymethyl methacrylate
Polaroid sheet: 3.6.12
Poly-
Polyacetals, Acetals: 3.7.1
Polyacetylenes: 3.7.2
Polyacrylamides: 3.7.3
Polyacrylic acid, CH2CHCO2H
Polyacrilimide: 3.7.4
Polyacrylonitrile synthetic fibre: 3.7.5
Polyamides, Dacron, Terylene, Nylon, Perlon, Natural polyamides: 3.7.6
Polybenzimidazoles, PBI, polybenzimidazole synthetic fibre: 3.7.38
Polybutadienes: 3.7.7
Polybutenes: 3.7.9
Polybutylene terephthalate, PBT: 3.7.8
Polycarbonates, PC: 3.7.10
Polycaprolactone, PCL: 3.7.11
Polychlorinated biphenyls, PCBs, biphenyl: 3.7.13
Polychloroprene, neoprene: 3.7.12
Polydioxanone synthetic fibre
Polyesters: 3.7.14
Polyester synthetic fibre, embedding resin polymer: 3.6.8
Polyethenes, PE, polyethylene, polyisobutylene: 3.7.16
Polyether ether ketones, PEEK: 3.7.39
Polyethers: 3.7.15
Polyethylene glycol: 3.5.4
Polyethylene oxide: 3.5.5
Polyethylene terephthalate, PET: 3.7.19
Polyhydantoin: 3.7.21
Polyhydroquinone-diimidazopyridine, M5 synthetic fibre, PIPD
Polyimides, PI, Polypyromellitimide "Kapton": 3.7.40
Polyisoprenes, isoprene, natural rubber: 3.7.22
Polylactic acid
Polymer foam: 3.5.1
Polymethanal: 3.7.23
Polymethyl methacrylate, PMMA, acrylic glass, e.g. Plexiglass, Perspex (Lucite): 3.7.24
Polyolefins, polyalkanes: 3.7.25
Poly(p-phenylene sulfide) synthetic fibre, (C6H4S)n, Reactions of chlorine with benzene: 13.4.6
Polyphenylenes, polyphenylene oxide PPO, polyphenylene sulfide PPS: 3.7.26
Polypropenes, polypropylene, PP, polyprene, (monomer propylene, C3H6): 3.7.27
Polypropenonitrile: 3.7.28
Polysilicates, silicates group, polysilicon: 35.14.1
Polysiloxanes, silicone rubbers, PVMQ: 7.2.7
Polystyrene, PS, Styrofoam: 3.7.29
Polysulfide rubbers: 3.7.30
Polysulfones: 3.7.31
Polytetrafluoroetheylene, PTFE, tetrafluoroethylene, polytetrafluoroethene, "Teflon": 3.7.32
Polytetrafluoroethylene, Magnesium with PTFE, 16.2.2
Polytetramethylene ether glycol, PTMEG: 3.7.33
Polytrifluorochloroetheylene, PTFCE: 3.7.32
Polyurethanes, PUR, (PU), "urethanes", poly-formaldehyde, (some are thermoset plastics): 3.7.34
Polyvinyl acetals: 3.7.35
Polyvinyl acetate, polyvinylacetate, PVAC, "PVA": 3.7.36
Polyvinyl alcohol, PVA, PVOH, 3.6.13.1
Polyvinyl chloride, PVC, polychloroethene: 3.7.37
PrimaLoft synthetic fibre
Qiana
Rayon polymer: 3.8.14
Retroglo synthetic fibre
Rubber polymer, cis-1.4-polyisoprene (latex of Hevea brasiliensis)
SAN, styrene and acronitrile: 3.8.3
Saran, (plastic): 3.6.13
Silicones, Volasil, thermoset plastics: 3.8.1
Silly string: 3.5.2
Silly putty: 3.4.11
Spandex polymer, Generic name for elastic fibres from polymers >85% segmented polyurethane
Styrenes: 3.8.2
Styrofoam: 3.7.29
Sulfur synthetic fibre
Super ball: 3.4.04
Synthetic fibres, synthetic resins: 3.6.14
Tactel synthetic fibre
Taklon synthetic fibre
Technora synthetic fibre, polyamide: 3.7.6
Teijinconex synthetic fibre, polyamide: 3.7.6
Terital polymer, Fibres from polyethylene terephthalate: 3.7.19
Terlenka polymer, Fibres from polyethylene terephthalate: 3.7.19
Terylene polymer, (condensation of terephthalic acid + ethan-1,2-diol), straight-chain polymer fibre: 3.7.20
Tests for plastics, natural fibres and synthetic fibres: 3.102
Thermoplastic polymers: 3.0.2
Thermosetting polymers: 3.0.3
Thinsulate synthetic fibre
Trevira polymer, Fibres from polyethylene terephthalate: 3.7.19
Triacetate polymer, Generic name for fibres from cellulose triacetate
Tricel polymer, Fibres from cellulose triacetate
Trogamid, polyamide: 3.7.6
Twaron synthetic fibre, polyamide: 3.7.6
Ultem (Trade name), Polyether imides are melt-processible imides linked by ether (-O-) groups
 in the main chain.
Urea-formaldehyde, thermoset plastics: 3.8.11
Vectran synthetic fibre
Vestolit polymer, Polyvinyl chloride
Vinalon synthetic fibre
Vinyls: 3.6.13
Vinyon synthetic fibre
Viscose polymer, Generic name for fibres from regenerated cellulose, cellulose xanthate forms
 viscose rayon textile fibres
Vulcanization: 3.6.11
Zylon synthetic fibre, PBO
Zytel polymer, Toughened nylon, various aliphatic polyamides: 3.7.6
9.0 Plastics manufacture
Process and Products
Machine processes
9.1.0 Extrusion
Profiles, tubes, pipes, sheets, films, cable sheathing
9.2.0 Injection moulding
Mouldings, e.g. cups, gear wheels, telephones, milk bottle crates
9.3.0 Blow moulding
Bottles and containers
9.4.0 Rotational moulding
Tanks, drums, household goods
9.5.0 Calendering
Plastic sheet
9.6.0 Foaming
9.7.0 Laminating
Plastic laminated with paper, wood, metal
9.8.0 Compression moulding
Mouldings, sheets, blocks
9.9.0 Thermoforming
Deep drawing of beakers, packaging, baths, boat hulls
Manual processes
10.0 Casting
Blocks, sheets, mouldings, coating
Mouldings, encapsulation
11.0 Foam pouring
Space filling, coating, large mouldings
12.0 Reinforcing
Mouldings, lining, coating
13.0 Manual Thermoforming
Welding and bending of pipes and craft shaping
3.0.1 Polymers
Order online: Expanding Snow Polymer
Order online: Expanding Spheres, super absorbent polymers
Polymers are large molecules built up by repetition of small, simple chemical units called monomers.
For example (+) glucose is the unit of starch, and ethylene (ethene) is the unit of polythene. Polymers
are long chain molecules formed by polymerization, the combination by step-by-step repetition of groups
of atoms called repeat units, e.g. -CO-O- in polyesters. The chain length of polythene is about 5000
ethene units. The mechanical properties of polymers depend on their molecular size. Polymers melt at a
characteristic temperature that may be changed by impurities and additives. Some polymers, e.g. forms
of polystyrene and forms of polypropylene can crystallize at a certain temperature to change their thermal
and mechanical properties, increase their density and contract more after moulding.
Synthetic polymers are formed by chemical reactions for making plastics where monomers are joined by
polymerization and condensation.
Homopolymers form from the same monomer, e.g. ethene, CH2CH2, is polymerized to form polyethene
(polyethylene) ... -CH2-CH2-CH2- ....
Heteropolymers (copolymers) are made from different monomers, e.g. ABS plastics are made form
acrylonitrile, butadiene, styrene copolymers. ABS is the generic name for plastics from acrylonitrile,
butadiene and styrene units
Synthetic resins are polymer compounds before curing.
Regular polymers normally crystallize and may be cooled from the melt so quickly to allow crystallization,
e.g. polyethylene terephthalate film is amorphous owing to cooling at a high rate.
Natural products, cellulose in wood and cotton, horn, rosins, raw rubber
Converted natural products, vulcanized rubber, vulcanized fibre, celluloid (cellulose nitrate), casein plastic
(artificial horn)
3.0.2 Thermoplastic polymers
Order online: Thermoplastic polymer, Polycaprolactone
Thermoplastic polymers, thermosoftening plastic, have long-chain molecules which soften on heating and
harden on cooling to a glassy state without significant chemical change. They can be melted and moulded
again and again. This plastic is heated to soften it, then squeezed to fuse it and to shape it by viscous flow.
Most polymers are thermoplastics. Usually have high molecular weight with weak Van der Waals bonds
between molecule chains that can be broken by heating. e.g. polyethylene, nylon, polystyrene, polypropylene.
3.0.3 Thermosetting polymers
Thermosetting polymers are extensively cross-linked to form 3-D networks that does not soften much
on heating. A network of strong covalent bonds forms during the initial curing so the material cannot be
remoulded. Thermosetting plastics have rigid cross-linked molecules, resist high temperatures, cannot be
softened after curing. insoluble, hard and brittle substances. They are polymers that once formed does not
melt on heating, charring instead. Its structure has cross-linking from one chain to the next produced by
chemical curing. These thermosets cannot be recycled, e.g. phenol resins (Bakelite), epoxy resins,
melamine-formaldehyde resin, polyimides, polyesters, silicones, fibreglass, urea-formaldehyde foam,
vulcanized rubber, some polyurethanes.
3.0.4 Phthalates
Phthalates, C6H4(COOR1)(COOR2) are esters of phthalic acid, [C6H4(COOH)2], used as plasticizers
and to make polymers and alkyd resins, and to soften polyvinyl chloride, (PVC). They are used to make
shower curtains, PVC piping and inflatable products. However, their use is being phased out in some
countries because of concern about possible risk to foetuses and young children.
3.0.5 Brominated Flame Retardants, (BFRs)
Brominated flame retardants, BFRs, used to reduce flammability of clothing and furnishings may cause
human health problems.
For example, hexabromocyclododecane, (HBCD), and tetrabromobiphenol A, (TEEPA) are toxic to
water organisms and may be present in polystyrenes and polyesters.
3.4.01 Glass transition temperature (Tg)
Glass transition temperature is the temperature when the material changes from glass to rubber
properties. Soda-lime window glass, (about 73% SiO2, 14% Na2O, 7% CaO, 4% MgO, 2% Al2O3)
has glass transition temperature, Tg, 564oC, and melting point, Tm, about 1500oC. At glass transition
temperature the viscosity drops suddenly. Amorphous polymers below Tg are hard and stiff but above
Tg are rubbery. The glass transition process is gradual. Semi-crystalline polymers have less change at
Tg and above Tg may not be brittle. An amorphous polymer has molecular chains in the irregular
arrangement at Tg are homogeneous and transparent because they do not contain crystals to scatter the
light. Natural chewing gum comes from chicle based on gutta-percha plasticized by triterpenes.
Commercial chewing gums are based on poly (vinyl acetate) PVA. If chewing gum is stuck to a carpet,
you can freeze it with ice to bring its temperature down to its Tg, then remove it as a solid. Plastic
containers made from recycled plastic has raised Tg because the mix of materials slows molecular
movement. In cold climates, below Tg the containers become brittle bins and crack easily if dropped.
Cotton is a cellulose polymer with Tg of 225oC. It absorbs water because the water molecules can slip in
between the polymer molecules plasticizes the cotton and lowers the Tg. When ironing cotton fabric, you
can sprinkle with water or use a steam iron to increases the plasticizing effect then remove by heat to raise
the Tg and set the fabric in a new shape. However, nylon fibres have Tg of 50oC and polyester has Tg of
69oC, so lower temperature ironing is needed! Steam ironing of wool breaks the disulfide bonds that keep
wool fibres in shape and then allows them to reform.
3.4.02 Chemical sources of polymer materials
Acrylonitrile-butadiene copolymer, acrylonitrile-butadiene styrene (ABS), acrylonitrile-styrene-butyl
acrylate (ASA), cellulose acetate butyrate (CAB), chlorinated polyethylene (CPE), ethylene vinyl
acetate (EVA), ionomer resins, e.g. poly(ethylene-co-methacrylic acid, (e.g. Surlyn),
melamine-formaldehyde resin, phenol-formaldehyde resin, styrene-acrylonitrile (SAN),
 urea-formaldehyde resin, polymer alloys
Polyacrylics (inc. PMMA), amide (e.g. nylon, 66), butadiene (high cis) elastomer, butadiene-styrene
elastomer, butadiene-styrene resins, butylene terephthalate (PBT), carbonate, epichlorahydrin, ester,
thermoplastic ester (thermoset), ethylene (LD), ethylene (LLD), ethylene (HD), oxymethylene
(polyacetal) phenylene oxide (e.g. Naryl), propylene copolymer, propylene homopolymer (PP),
styrene (PS) urethane-prepolymer, urethane-thermoplastic, vinyl acetate (PVA), vinyl chloride (PVC),
vinyl chloride copolymer, poly-diallylcarbonate, Columbia resin, CR39, CR64, EX80, is used for
plastic optical lens, embedding and casting.
3.4.2 Addition polymers
See diagram 16.3.4.2: Vinyl polymers
Addition polymerization occurs when identical monomers link under high temperature and pressure.
The reactive group is the carbon to carbon double bond [C=C]. For example many units of ethylene
(ethene [CH2=CH2] combine to form polyethene (polythene) [-CH2-CH2-CH2-CH2-]. That is the
only product of the reaction and it has no definite chemical formula. For example phenylethene
polymerizes to form poly(phenylethene), polystyrene, styrene.
Addition polymers are called thermoplastic (thermosoftening) polymers because they melt easily.
They may be recycled because they can be melted and used again but, when they burn, they may
form poisonous gases.
Polymers called polyelectrolytes that can absorb up to 1 000 times their weight in water, gel
capacity, are known as "Super Absorbents" and "Water Crystals". When dry, the polymer is a
white powder and when in gel form it is a transparent gel. It is used in diapers, bed pads, fire
control, spray drift control, seed germination, soil conditioning, menstruation period pads, and
hydroponics. It is sensitive to the salts in hard water so dissolved minerals decrease absorption
capacity.
Addition polymerization, chain polymerization involves activating monomer molecules with a catalyst,
benzoyl peroxide, that splits to give two free radicals that reacts with a monomer to form another
free radical (initiation), that reacts with with more monomers to form a polymer chain. The two
free radicals react together to stop the reaction or react with another chain to form branching chains.
Chain growth polymers include polyethylene, vinyl polymers, polybutadiene
3.4.2.8.1 Acrylic acid, "acrylics"
Order online: Super Slurper Polymer, hydrophilic sodium polyacrylate,
Poly(propenenitrile), acrylic, "Acrilan", "Courtele", (monomer H2C=CHR, where R = -C≡N,
note triple bond). Acrylic acid is manufactured from propylene (from catalytic cracking of petroleum)
in two steps via acrolein in a gas phase using special catalysts.
CH2=CHCH3 (propylene) + O2 --> CH2=CHCHO (acrolein) + H2O
CH2=CHCHO + 1/2O2 --> CH2=CHCO2H (acrylic acid)
Acrylics may refer to any of the following chemicals derived from acrylic acid, e.g. acrylic fibre
(acylonitrile), acrylic paint in an acrylic emulsion), acrylic resin (e.g. polymethyl acrylate) acrylic glass
(polymethyl
methacrylate, PMMA), acrylate polymers.
Commercial
Acrylic cement, clear fluid, 29 mL
Acrylic offcuts, white, clear, colours
Acrylic sheets 800 mm width × 600 mm depth × 3 mm height, clear
Acrylic sheets 800 mm width × 600 mm depth × 3 mm height, translucent red, grey, amber
Acrylic sheets 800 mm width × 600 mm depth × 3 mm height, opaque, red, yellow, white, green
Acrylic sheets 800 mm width × 600 mm depth × 3 mm height, fluorescent, pink, green, orange, blue, black
3.4.3.0 Condensation polymers
Condensation polymers need two, usually different, reactive monomers with two functional groups to link
 with the loss of a small molecule, e.g. water or hydrogen chloride, to form a polymer. The reaction is
similar to the formation of esters and starches. These reactions may be thermoplastic (softening on
heating) or thermosetting (do not soften on heating). You cannot recycle thermosetting plastics.
3.4.3.1 Epoxy resin polymers
See 16.11.8: Epoxy, epoxy resin
Epoxy resin polymers are formed by polymerizing epoxide compounds [R1COCR2] with phenols
[C6H5O-] epichlorhydrin and bisphenol-A, BPA. Some are thermoset plastics. They are used as
surface coatings, liquids, resins, hardeners, fibre-reinforced sports equipment, aeroplanes, boat parts,
casting resins, and embedding electronic components because of resistance to chemicals. They are also
 used as adhesives that have a two pack system of a resin and a hardener, silicon tetrachloride,
Epoxy, contains group -C-O-C, as in epoxides, a cyclic ether, thermosetting synthetic resins, in
coatings to resist chemical attack and adhesives, hardened by polyamines to form cross-linkages. Have
an oxygen atom attached to two carbon atoms of a carbon chain or ring system, so are cyclic ethers,
e.g. 1, 2-epoxypropane. Epoxy resins are fibre glass resins. Bisphenol-A, (BPA) is used in polycarbonate
containers, reusable water bottles, and metal-based food and beverage containers. However, the use of
bisphenol-A, (BPA), for containers is banned for use in baby bottles in the European Union, France,
Denmark, Canada, some US states, and Australia. because it may slowly dissolve in the contents and
affect foetal brain development and be an endocrine disrupter affecting the reproductive system. Canada
has classified bisphenol-A as a toxic substance.
3.4.3.2 Polyacetals
Polyacetals, polyoxymethylene resin, acetyl resin, polyformaldehyde, POM, "Kematal", "Delrin" resist
abrasion and resist organic solvents and water. This moulding polymer is widely used in engineering
products, e.g. gear wheels, plumbing to replace brass or zinc and in pens. It may be copolymerized
with ethylene oxide to increase stability and not become depolymerized.
3.4.12 Alginate polymer
Medicines to relieve heartburn, e.g. Gaviscon, may contain sodium alginate as well as sodium
bicarbonate and calcium carbonate. An alginate is a polysaccharide from a seaweed, mainly
D-mannuronic acid and L-glucoronic acid subunits. Alginates are also used a food thickeners
polymer, E400 Alginic acid (from seaweed) (vegetable gum, thickener, emulsifier) (used in flavoured
milk, ice blocks, yoghurt) E401 Sodium alginate (vegetable gum) (as in E400).
Pour a stream of the heartburn medicine, or 2 g of the sodium salt of alginic acid in 100 mL of
deionized water, into calcium chloride solution, 1g in 100 mL of deionized water. Worm-like masses
form as the polymer becomes cross-linked. As soon as they form, lift out some worm-like masses,
feel their texture, and put them in a saturated sodium chloride solution in a beaker. Shake the beaker
to see the worm-like masses dissolve to form a cloudy solution. The cross-linking in the presence of
Ca2+ has disappeared as Na+ replaces the Ca2+.
3.4.04 Super ball
Super ball is made from polybutadiene with small amounts of sulfur to reinforce the material and
serve as a vulcanizing agent. The ball is moulded under very high pressure and temperature and is
said to have a 92% resiliency, about three times the resiliency of a tennis ball. It can continue to
bounce for about a minute after being dropped from a short height.
3.4.1.0 Natural polymers, natural rubber
See 34.5.02: Hooke's law, elastic limit, deforming force, stress and strain
Order online: Rubber Flubber Experiment Kit, natural polymer, latex
Natural polymers occur as brittle glassy gums and resins in plants, e.g. conifers, and as
polysaccharides, e.g. starch. Natural rubber is a polymer of isoprene CH2=C(CH3)CH=CH2,
cis-1,4-polyisoprene, in which all the -CH=CH-= groups are cis. The polymer chains in natural
rubber are elastic in the sense that the chains can be unravelled without coming apart, i.e. the rubber
can stretch. Elasticity was improved by cross-linking with sulfur, using the Goodyear process to
produce vulcanized rubber. Stretching aligns the random chains, and temporarily crystallizes and
toughens rubber so that rubber tyres do not form cracks. Rubber is not very elastic in the Hooke's
law sense of stress being proportional to strain. The transisoprene polymer, trans-1,4-polyisoprene,
occurs in tropical trees in the latex of Palaquium oblongifolium, Sapotaceae family, same chemical
as natural rubber, polyisoprene, but with trans not cis bonding.
Rubber bands are made mostly of natural rubber cured by heat. Petrol can dissolve the cross-linkages
between the polyisoprene molecules to allow water molecules to move in between them and swell the
rubber band. A standard way to test the strength of cross-linkages in substances is to put them in
toluene and measure the increase in volume.
Collect, examine and describe different addition polymers, e.g. plant gums, natural starch.
3.5.1 Polymer foam
See diagram 16.3.4.10: Polyurethane
The latex of natural rubber has a low glass transition temperature so foam rubber is always flexible.
Polystyrene has a high glass transition temperature so its foams are rigid. Polyurethane foams can be
flexible or rigid depending on the formulation so they can be used for soles of shoes. The foaming
agent may be air or a "blowing agent" that decomposes to a gas on heating.
3.5.2 "Silly string"
It is reported to be a mixture of polyisobutyl methacrylate, sorbitan trioleate and a solvent that
evaporates in the air contained in an aerosol can. Release of pressure causes a thin spurt to shoot
out and harden in the air as a string. The product is a nuisance, but it is supposed to be useful for
detecting hidden wires in dark places, e.g. trip wires.
3.5.3 Plastics recycling code, recycling symbols
See diagram 16.3.5.1: Recycling code
The codes from the Society of the Plastics Industry are found on the bottom of plastic packaging.
1 PETE, Polyethylene terephthalate, commonly recycled. relatively safe plastic designed for single use
2 HDPE, High density polyethylene, commonly recycled, relatively safe plastic for use in food and
drink containers
3 V, Vinyl chloride / Polyvinyl Chloride (PVC), not commercially recycled, may contain and leach
dangerous chemicals
4 LDPE, Low density polyethylene, less commonly recycled, relatively safe plastic for use in food
and drink containers
5 PP, Polypropylene, not commercially recycled, relatively safe plastic for use in food and drink
containers
6 PS, Polystyrene, not commercially recycled, may contain and leach dangerous chemicals
7 PC or Other, Polycarbonates, layered or mixed plastic, with no recycling potential so must be
disposed of by land fill, may contain and leach dangerous chemicals
Uncoded plastics are not usually recycled but disposed of in land fills.
3.5.4 Polyethylene glycol, PEG, HO-CH2-(CH2-O-CH2)n-CH2OH, polymer of ethylene oxide,
different molecular masses measured in g / mol, melting point depends on formula weight, low toxicity
but toxic impurities can damage broken skin, (Trade name, "Carbowax"), used as initiator of
polymerization process, printer ink, "Paintball" bullets, wood in salvaged ships, high osmotic pressure
solutions, monoclonal antibody production, non-ionic surfactants for cosmetics and pharmaceutics,
e.g. laxatives, toothpaste, eye drops.
3.5.5 Polyethylene oxide, PEO, POE (repeating unit, -CH2-CH2-O-), water soluble, used in
cosmetics, toothpaste, water used for fire fighting.
3.5.6 Casein, milk casein, casein plastic (artificial horn)
See 3.100: Prepare plastic with milk casein
Milk casein, phosphoprotein thermoplastic polymer, for insulators, buttons, handles, adhesives,
 artist's priming paint
Casein formaldehyde
3.5.7 Celluloid, thermoplastic, synthesized from cellulose nitrate, cellulose-based fibres (rayon,
cellophane), viscose cellulose film, celluloid A flammable thermoplastic that decomposes, made from
nitrocellulose + camphor (not used nowadays except for ping-pong balls, guitar picks, spectacle frames,
hair adornments). Polynosic fibres are rayon fibres with improved qualities of uniformity. The first
thermoplastic, discovered 1862, but the name "celluloid" in 1870. Also, cellulose propionate, cellulose
butyrate, ethyl cellulose
Celluloid polymer, Cellulose nitrate plasticized with camphor
3.5.8 Cellulose acetate, "acetate", zylonite, (cellulose ethanoate), Cellulose acetate butryate, CAB,
thermoplastic, used in cigarette filters, fibres
Cellulose triacetate, TAC, triacetate, [C6H7O2(OOCCH3)3]n, used in clothing fibres, packaging,
photographic film, semipermeable membrane
3.5.9 Cellulose nitrate, nitrocellulose, flash paper, guncotton, made from cellulose (starch, wood,
cotton) + nitric acid, highly flammable, explosive
3HNO3 + C6H10O5 --> C6H7(NO2)3O5 + 3H2O
3.5.10 Collodion
Cellulose nitrate dissolved in a mixture of ethanol or diethyl ether, cellulose tetranitrate, used as a
medicinal coating. Also an early photographic process, cellulose nitrate + soluble iodide coats a
glass plate then in darkroom immersed in silver nitrate to form silver iodide. Then the wet plate
was exposed in a camera, then developed with pyrogallic acid and fixed with sodium thiosulfate
or potassium cyanide solution.
3.6.0 Polymer terminology
3.6.1 Polymer Density
Density range = g / cm-3
EPS, expanded polystyrene 0.02-0.06
PP, polypropylene 0.89-01.91
LDPE, low density polyethylene 0.91-0.93
HDPE, high density polyethylene 0.94-0.96
PS, polystyrene 1.04-1.1 1
PVC, polyvinyl chloride 1.20-1.55
PET, polyethylene terephthalate 1.38-1.40
3.6.2 Elastomer polymers
A polymer material with elastic properties, namely the ability to snap back to the original dimensions
after distortion. Cross-linked molecules but with fewer linkages than thermosets, can swell in solvents
to become rubbery, regain shape after distortion.
3.6.3 Initiator polymer
A substance used to start a chain polymerization reaction, e.g. a free radical. Polyethylene glycol is
used as initiator of polymerization processes.
3.6.4 Isomerization polymer
Isomers are molecules with the same molecular composition and relative molecular mass but different
arrangement of atoms, e.g. butane and isobutane are both C4H10. Isomerization is the rearrangement
of the geometry of a molecule without changing its overall formula.
3.6.5 Monomer polymer
A simple molecule that is joined to others to form a dimer, trimer, or polymer.
3.6.7 Plasticizers polymer
This is an additive that makes a polymer material more flexible or less rigid.
3.6.8 Polyester embedding resin polymer
A viscous liquid of a polymerized unsaturated polyester dissolved in styrene monomer.
The methyl ethyl ketone peroxide catalyst cross-links the styrene to the double bonds in the polyester.
3.6.9 Polymerization polymer
The process by which single units, monomers, are joined to form a giant molecule, polymer.
A linear polymer has links only in one dimension forming a chain. A cross-linked polymer has
cross-links between chains.
3.6.10 Polymorphism polymer
Substance occurs in distinct solid forms.
3.6.11 Vulcanization
See: Latex
Vulcanization is a thermosetting process to treat rubber and rubber-like polymers with sulfur and heat to
improve elasticity, and strength or to harden substances by forming cross-links between polymer chains.
Sulfur is added to the liquid latex of natural rubber (polyisoprene) to create cross-linkages. Latex
collected ("tapped") from the para rubber trees (Hevea brasiliensis) or other "rubber trees", by cutting
into the bark is coagulated with acid, is collected in a latex bulking and blending tank, coagulated with
formic acid or acetic acid, rolled into ribbed smoked sheets and left to dry in a smoke house. This soft
rubber is called crepe rubber and was formerly used for the soles of sandals. Very hard rubber is
ebonite, e.g. indoor bowling balls.
3.6.12. "Polaroid" sheet
A piece of birefringent material that absorbs light in one of the directions strongly, while transmitting
much of the other. Polaroid is made from plastic by adding a long chain molecule dye before stretching
so that the dye gets orientated as well as the plastic. Polaroid may be 1. iodoquinine sulfate in
nitrocellulose polymer film, 2. iodine in polyvinyl alcohol. Polaroid is dichroic, i.e. it absorbs light
depending on the incident direction.
3.6.13 Vinyls, vinyl polymers, thermoplastic, polyvinyl, CH2=CH2, odourless, tasteless
See diagram 16.3.4.2: Vinyl polymers, vinylidene chloride, Polyvinylidene
V is the plastic identification recycling code 3 for vinyl chloride / polyvinyl chloride (PVC) used for
food wrap, vegetable oil bottles but not commonly recycled except in tests.
polyvinyl acetate, (PVA), vinyl ethanoate, CH2COOCH=CH2, vinyl acetate monomer, used for
adhesives and latex paints
polyvinyl alcohol, water-soluble
polyvinyl butyral, PVB (interlayer in laminated safety glass screens in automobile windshields, cracks in
 glass windscreens), e.g. "Butacite"
polyvinyl carbazole, (xerography)
polyvinyl formal, (lacquers, coatings)
polyvinyl pyrrolidone, water-soluble, (cosmetics, with methyl methacrylate in soft-contact lenses)
polyvinylidene chloride, PVDC, (vinylidine chloride monomer, 1,1-dichloroethylene, repeat unit,
-CH2-CCl2-, cling wrap (not Australia), Saran wrap, freezer bags) (coating for PET beer bottles,
chemical-resistant piping), (co-polymer with PVC in Saran polymer, >80% vinylidene chloride units )
polyvinylidene fluoride, (repeat unit, -CH2-CF2-), (transducers in liquids, hydrophones)
polyxylylene, (dielectric film)
29.9.4 Grooves in a vinyl disc gramophone record
3.6.13.1 Polyvinyl alcohol, PVA, PVOH, synthetic polymer, (C2H4O)x, used in adhesives,
textile size, synthetic fibres
Order online: Bouncing Ball Kit, PVA (polyvinyl alcohol), make a high bounce ball
Order online: Colour changing heat sensitive putty, PVA (polyvinyl alcohol)
3.6.14 Synthetic fibres are manufactured by synthesis of a linear polymer then extruded molten
through fine holes, spinneret, mainly
polyester, nylon, acrylic and polyolefin. Synthetic resins are made by condensation reactions, e.g.
phenol and formaldehyde, urea and formaldehyde, glycerol and phthalic anhydride.
3.7.1 Polyacetals, thermoplastics, synthesized from from aldehyde, (polyoxymethylene resin, POM),
acetal resin, polyformaldehyde
Acetals, acetal [RCH(OR')2, CH3CH(OC2H5], smelly liquid, (gears, bearings, telephones, radios,
television components)
See 16.1.3.8, Acetals, synthesized by alcohol with aldehyde
3.7.2 Polyacetylenes, -CH=CH-, not yet developed as a plastic
3.7.3 Polyacrylamides, synthesized from 2-propenide, transparent, cross-linked, (used in
polyacrylamide gel electrophoresis [PAGE] to separate nucleic acids and proteins) A polyacrylate
is a polymer of acrylic acid ester.
3.7.4 Polyacrylimide, synthesized from methacrylic acid and methacrylonitrile copolymer + urea,
(rigid foam articles, e.g. propellor blades)
3.7.5 Polyacrylonitrile, PAN, thermoplastic
See diagram 16.3.4.2: Acrylonitrile, polyacrylonitrile (at bottom of diagram)
Acrylic fibres, synthesized from at least 85% acrylonitrile, polyacrylonitrile from monomers vinyl
acetate or methyl acetate, (textile fibres, acrylic resin, Trade name "Orlon", "Acrilan"). Polypropenonitrile
is synthesized from the monomer propenonitrile (acrylonitrile monomer, vinyl cyanide) [CH2=CHCN].
acrylics (acrylic acid, CH2,CHOOH), (acrylonitrile, CH2,CHCN) acronitriles, e.g. propenenitrile (fibres)
3.7.5.1 ABS, generic name for plastics from acrylonitrile, butadiene and styrene units
(telephone sets, shoe soles, automobile parts)
3.7.6 Polyamides
H2N-R+R'C=O(OH) --> R'C=ONHR + H2O
amine + carboxylic acid --> amide + water
NH2-XNH2 + C=O(OH)YC=O(OH) --> -NH-X-NH-C=O-Y-C=O-NH- + xH2O
diamine + dicarboxylic acid + --> polyamide + water
Polyamides are natural and synthetic fibres, polymers with the amide group, -CO-NH-, repeated
along the chain. Natural polyamides include hair, silk and wool. Polyamide PA 6 (natural) is a very
useful plastic because it has has good abrasion resistance for sliding elements, impact strength sand
high ductility. Its properties can be modified by additional stabilzers to change its properties.
Thermoplastic, condensation polymerization, synthesized from amino group with carboxylic acid
group to form H bonding between molecules with water or HCl eliminated. Used in typewriter keys,
gear wheels, screws, fibres, synthetic fabric "Dacron" "Terylene") thermoplastic.
benzene-1,4-diamine + benzene-1.4-dicarboxylic acid --> Kevlar + water
NH2-benzene-NH2 + HOC=O-benzene-C=OOH --> -NHbenzene-NH-C=O-benzene-C=O-NH + xH2O
3.7.6.1 Nylon
See diagram 16.3.4.7: 6,6 nylon and 6-nylon
Nylon polymer is a generic name for polyamides thermoplastics, synthesized from amino group with
carboxylic acid group to form H bonding between molecules, -CO-NH-. The polyamid fibre nylon,
(Germany Perlon)
Nylon is generic name for polymers with amide groups in main chain. The nylons are aliphatic
homopolymer polyamides.
nylon 6, polycaprolactam, (Perlon), synthesized by ring-opening polymerization of caprolactam, not
condensation, (caprolactam has 6 carbons)
nylon 6,6, synthesized from hexamethylenediamine (1.6-diaminohexane) and adipic acid
(hexane-1,6-dicarboxylic acid), (6 carbon diamine and 6 carbon adipic acid)
nylon 6,10, synthesized from 1,6-diaminohexane (6 carbon atoms) and sebacoyl chloride
(10 carbon atoms)
1,6-diaminohexane: NH2-(CH2)6-NH2
hexane-1.6-dicarboxylic acid: HO-C=O(CH2)4-C=O-OH
Commercial
Nylon utensils, for use on non-stick surfaces, egg turner, 320 mm
3.7.6.1.1 Dacron, thermoplastic, polyethylene terephthalate, PET, (food containers, fibres,
thermoforming), aramid fibres are polyamides synthesized from aromatic groups attached to amide
links, natural polyamides, -CO-NH-, include hair, silk, wool.
See 16.3.4.0b: Aramids
3.7.7 Polybutadiene, elastomer, synthetic rubber, polymer of 1,3-butadiene
3.7.8 Polybutylene terephthalate, PBT, synthesized from 1,2-butanediol and terephthalic acid,
(thermoplastics)
3.7.9 Polybutenes, synthesized from 2-methyl propylene, very high molecular weight, resists
moisture, (hot and cold water pipes)
3.7.10 Polycarbonates, PC, thermoplastic, synthesized from bisphenol A, functional group -O.CO.O-,
e.g. bisphenol A (BPA) is used for bullet-proof glass and CR-39 is used for optical lenses
See 3.5.3, Plastics recycling code, Polycarbonate or Other, 7 PC or Other
Polycarbonates retain their dimensions and resistance to impact and wide range of temperatures. The
functional carbonate group is -O-CO-O-. It is widely injection mould to make aircraft interiors,
automobile parts, baby bottles, battery cases, bus windows, citrus juice bottles, compact disks,
cutlery, dental sealants, eye wear, fire masks, five gallon water bottles, helmets, injection moulded
battery cases, lining of tin cans, milk jugs, office equipment, oven baking bags, packaging, reusable
water bottles, safety glasses and goggles, safety windows, sippy cups, snow boards, spectacle lenses,
sunglasses, traffic signs. The trade names include, "Lexan", "Makrolon" ("CR39"), Columbia Resin 39,
sunglasses, spectacle lens).
The bisphenol A used to make polycarbonates can leach into the environment when heated.
Bisphenol A is suspected of being a hormone blocker with multiple health effects including miscarriages,
 reduced sperm count and cancers. In some countries, baby bottles and sippy cups made from
polycarbonates are banned.
Commercial
Serving jugs, polycarbonate, 2000 mL
Polycarbonate cutlery, heavy duty and re-usable, suitable for industrial and prison use, soup / dessert
spoon, pack / 12
3.7.11 Polycaprolactone, PCL
Order online: Thermoplastic Polymer
Biodegradable polyester, [-O-(CH2)5-Ć=O] used in resins, splints and modelling.
3.7.12 Polychloroprene, neoprene, elastomer, synthesized by polymerization of chloroprene,
chloropene isomer, synthetic rubber, resists weather, (electrical insulation, car fan belts, wet suits,
rubber boats)
Neoprene (polychloroprene) was the first synthetic rubber used in industry. The monomer is
2-chlorobuta-1,2-diene, when vulcanized is very resistant to oils, chemicals, sunlight, ozone, and
heat.
chloroprene, C4H5Cl, 2-chloro-1,3-butadiene, CH2=CCl-CH=CH2
Neoprene polymer, Elastomeric polymers and copolymers from chloroprene
3.7.13 Polychlorinated biphenyls, PCBs, synthesized from biphenyl (C6H5C6H5) and chlorine,
moderately toxic, probably carcinogenic, environmental danger, banned in secondary schools,
(electrical insulators, coolant in transformers)
3.7.14 Polyesters
See diagram 16.3.4.8: PET
RC=O(OH) + HOR' --> RC=O(OR')
carboxylic acid + alcohol --> ester + water
Diols have two -OH groups, HO-X-OH, and dicarboxylic acids have two carboxylic acid groups,
C=O(OH)YC=O(OH), where X and Y, usually, = -CH3.
HO-X-OH + C=O(OH)YC=O(OH) --> -O-X-O-C=OYC=O + xH2O
diol + dicarboxylic acid --> polyester + water
Polyester synthetic fibre, UP, thermoset plastics, thermosets, synthesized from condensation reaction
of polyhydric alcohol (e.g. monoetrhylene glycol) with polybasic acid, (e.g. terephthalic acid, or
dimethylterephthalate) to form ester link [ester bond, -CO.O-], linear polyester fibre, unsaturated
polyester resins, synthesized from dicarboxylic acids, (glass fibres "fibre glass", reinforced tanks,
kiosks, boats, casing resins, film base), polyester rubber, thermoplastic, elastomer, synthesized from
 polytetramethylene ether glycol and polybutylene terephthalic, (moulded items), [polyester rubber is
not the same as acrylic rubber]
includes polyethylene terephthalate, polybutylene terephthalate (PBT), acrylic rubbers, polyester
thermoset resins
Polyester polymer, Generic name for fibres from polyesters >85% terephthalic acid and ethylene glycol
units
Polyester unsaturated polymer, Thermosets from maleic acid / ethylene glycol polymers cross-linked with
polystyrene
Examples: Polyethylene terephthalate PET a semi-aromatic copolymer, Terylene, Crimplene, Dacron,
Trevira
3.7.15 Polyethers, long chain glycols made from ethylene oxide, used for antistatic and emulsifying
agents, e.g. PTMEG, polytetramethylene ether-glycol.
3.7.16 Polyethylene, (Trade name, Polythene), thermoplastic
Poly(ethene), polythene, alkathene, (monomer H2C=CHR, where R = -H). Polyethylene polymer is
 made by addition polymerization of the monomer ethylene (ethene, CH2=CH2). Polyethylene, PE,
polythene, polyethene, polymethylene), (ethylene, ethene monomer), used for plastic bags, has
different densities with different functions
See 3.5.3, Plastics recycling code, Low-density polyethylene, 4 LDPE, High-density
polyethylene, 2 HDPE
Let R-O-O. = a free radical initiator
R-O-O. + CH2=CH2 --> R-OOCH2-CH2
R-OOCH2-CH2 + CH2=CH2 --> R-OOCH2-CH2-CH2
R-OOCH2-CH2-CH2. + CH2=CH2 --> R-OOCH2-CH2-CH2-CH2-CH2
Final product, polyethylene, (CH2)n, a linear high density compound.
Polyethylene is used for bottle crates, bottles, bin liners, film and sheeting, garbage bins ["Wheely bins"],
electrical insulators, laboratory wash bottles, moulded and extruded objects, packaging film, pipes,
plastic bags, pressure pipes, toys. Polyethylene has a waxy feel and is acid resistant. Polyethylene
(LDPE) is opaque, white, soft, flexible, impermeable to water vapour, unreactive towards acids and
bases, absorbs oils and softens, melts at 100 to 125oC, does not become brittle until -100oC,
oxidizes on exposure to sunlight, subject to cracking if stressed in presence of many polar compounds.
3.7.17 LDPE is the plastic identification recycling code 4 for low density polyethylene used for
aerosol caps, ball pen ink tubes, disposable pipettes, freezer plastic bags, lemon juice containers,
plant pots, polyethylene film, plastic tubing, "plastic lumber", e.g. fence posts., sauce squeezing
containers, shrink wrap and garment bags that may be washed and pelletized to be recycled as
plastic rubbish bags.
3.7.18 HDPE is the plastic identification recycling code 2 for high density polyethylene bottles called
"natural" because of its natural colour that can be recycled in different colours or if already a mixture of
colours can be dyed black, pelletized and injection moulded to make aerosol caps, cable coverings,
carrier bags, cereal box liners, detergent bottles, flower pots, garbage containers, injection moulding wire,
motor oil containers, non-food containers, piping, plastic bags, plastic pipes, shampoo bottles, yoghurt
cups. HDPE is a relatively safe plastic and can be used for food and drink containers of milk and fruit
juices and containers of household cleaners and chemicals.. Polyethylene (HDPE) is similar to LDPE,
 but is more opaque, denser, mechanically tough, more crystalline and rigid. HDPE shrinks more when
cooling in the mould.
3.7.19 Polyethylene terephthalate, PET, thermoplastic
Polyethylene terephthalate (PET) is transparent, high impact strength, impervious to acid and atmospheric
gases, not subject to stretching. PET is used for light-weight, shatter proof soft drink, soda and water
 bottles and containers, peanut butter jars, cooking oil bottles, oven ready meat trays, microwavable meat
trays, detergent containers, textiles and carpets. Fibres from polyethylene terephthalate include "Melinex",
Terlenka, Terylene, Trevira. The drink bottles used to have a second black polyethylene as a cup on the
bottom for a strong base but now have a bottom with five convolutions. PET is a birefringent
2-dimensional orientated plastic.
See 3.5.3, Plastics recycling code, Polyethylene terephthalate, 1 PETE,
PET bottles can be colour-sorted, ground into pieces and washed to sink while caps and labels float off.
PET pellets can be recycled as bottles and fibres, e.g. carpets.
3.7.20 Terylene polymer is formed by condensation of terephthalic acid + ethan-1,2-diol to form a
straight-chain polymer fibre.
3.7.21 Polyhydantoin, plastic with aliphatic and aromatic rings in the main chain, heat-resistant, used
in insulating film and wire enamel in electric motors. Polyparabanic acids polymer has similar properties.
3.7.22 Polyisoprene, elastomer, diene polymer, natural rubber is mainly cis-1,4-polyisprene, from
Hevea brasiliensis, main monomer isoprene, -CH2=C(CH3)CH=CH2-, 2-methyl-1,3-butadiene, also
made synthetically, cis polyisoprene, isoprene rubber. Gutta percha is mainly trans-1,4-polyisprene.
3.7.23 Polymethanal, is synthesized from methanal by evaporation of methanal solution
3.7.24 Polymethyl methacrylate, perspex, PMMA, acrylic resin, polymethymethacrylate,
polymethyl 2-methylpropenoate, methyl methacrylate, thermoplastic transparent polymer,
 (Trade names, "Perspex", "Lucite", "Plexiglass").
See diagram 3.4.2: Methyl methacrylate, polymethyl methacrylate
PMMA is used for acrylic "glass" glazing, optical devices, perspex chips, perspex stirring rod,
plexiglass, reflectors, domes, safety glass, aircraft windows, baby baths, traffic signs. Perspex is made
by the polymerization of the monomer methyl methacrylate with lauroyl peroxide as a catalyst. This
reaction is highly exothermic if the concentration of the organic peroxide < 1% by weight. Has very
high molecular mass when in sheet form.
3.7.25 Polyolefins, polyalkanes, hydrocarbon polymer
Polymers formed from olefin monomers, e.g. polyethylenes, polypropylenes, and poly(4-methylpent-1-ene),
a transparent brittle plastic liable to cracking.. Polyolefin fibres are used in textiles.
3.7.26 Polyphenylenes are heat-resistant polymers formed from chains of linked benzene rings,
Polyphenylene oxide, PPO, [poly-(2,6-dimethyl-p-phenylene ether], usually blended with polystyrene
to form "Noryl" plastic.
Polyphenylene sulfide, PPS, has linking group -S_ in main chain, extremely heat-resistanr and
fire-resistant but brittle, so used in plastic moulded parts of motor vehicle engines.
3.7.27 Polypropenes, PP, polyprene, polypropylene, thermoplastic, synthesized from propylene
See 3.5.3: Plastics recycling code, Polypropylene, 5 PP
Poly(propene), polypropylene, (monomer H2C=CHR, where R = -CH3). Polypropene is made from
the monomer propene (propylene) [Repeat unit, -CHCH3=CH2]. Polypropene is used for automobile
parts, bottle caps and tops, bottles, bowls, buckets, car battery housings, carpets, chairs, clouded
plastic containers, crates, drinking straws, fibres (ropes), films, food containers, food wraps, heavy
duty bottles, medical applications, medicine bottles, moulding materials, piping, plastic buckets, sheets,
take-out (take-away) containers, tubing connectors. Polypropylene is opaque, high melting point
(160-170oC) high tensile strength and rigidity, lowest density commercial plastic, impermeable to liquids
and gases, smooth surface with high lustre. Low density polypropylene that is not commonly recycled
except in tests. Australian banknotes are made from biaxially-orientated (stretched two ways)
polypropylene. Parts of these banknotes are transparent.
3.7.28 Polypropenonitrile is used to make acrylic fibres (Orlon knitted fabrics, imitation fur and carpets,
acrilan textile fibres). Mixed polymer SAN made from styrene and acrlonitrile used for latex paints and plastic
 plates. Mixed polymer ABS made from acrylonitrile, butadiene and styrene, used for telephone sets, shoe
soles, car parts.
3.7.29 Polystyrene polymer, thermoplastic, (PS, polyphenylethene)
See 3.5.3, Plastics recycling code, Polystyrene, 6 PS : See 3.8.2: Styrenes
Poly(phenylethene), polystyrene, (monomer H2C=CHR, where R = -benzene). Phenylethene
polymerizes to form poly(phenylethene), polystyrene, styrene.
Polystyrene, PS, does not degrade so causes widespread pollution but it can be recycled. Polystyrene
polymer (polyphenylethene) is made from the monomer phenylethene (styrene), Styron thermoplastic,
Styropor cellular thermoplastic. Polystyrene is used for Aspirin bottles, ball pens, balls for atomic
models, coat hangers, compact disk cases, cutlery, disposable cups, plates and bowls, and cutlery,
disposable Petri dishes, electrical insulation, electronic housing, foam packing materials, foam food
containers, heat insulation, insulation, meat trays, medical products, moulded objects, plastic egg
cartons.
Commercial styrene contains a stabilizer that must be removed by shaking the liquid with sodium
hydroxide solution before starting polymerization. To initiate polymerization use lauroyl peroxide
instead of benzyl peroxide because it is less toxic. Styrene has a noxious odour at low
concentrations. Limit experimental activity to < 2 g per activity per person or group. Also,
(polystyrene-butadiene-styrene) elastomer exists. Polystyrene can leach styrene to the environment
from land fills, smoke, car exhaust fumes and building materials. Styrene poses multiple health risks
 judging by research with animals.
Polystyrene foams are good thermal insulators suitable for building insulation, e.g. "Styrofoam",
"rigid foams". It is a cellular plastic from polystyrene.
Expanded polystyrene, EPS, is a rigid closed-cell foam made of pre-expanded polystyrene beads
for building insulation, packing fragile items inside boxes, fast food packaging meat packaging trays
and egg boxes. The rigid panels are known as bead board.
Lustron polymer, Thermoplastic polystyrene. Thermoplastic polystyrene, solid protective packaging,
take-out (take-away) containers, throwaway utensils, toys, toys, yoghurt containers.
3.7.30 Polysulfide rubbers
Polymers with linked sulfur atoms in the main chain, -S-S-, as viscous pre-polymer fluid used to seal
joints in building construction, vulcanized to form fuel-resistant plastics for lining aircraft fuel tanks.
3.7.31 Polysulfones
Polymers with aromatic links in the main chain and using sulfonyl functional group, -SO2-, non-crystalline
and transparent, heat-resistant uses, e.g. microwave ovens.
3.7.32 Polytetrafluoroetheylene, PTFE, thermoset, synthesized from tetrafluoroethene
See diagram 3.4.2: Tetrafluoroethylene, Polytetrafluoroethylene, (PTFE)
Tetrafluoroethylene, (heat-resistant surfaces, gaskets, insulation, coating for bearings because low
coefficient of friction, moulding material, non-stick frying pan coatings, chemical-resistant film). However,
some people report that if a canary or other small caged bird is situated near a teflon-coated frying pan
heated to high temperature, the canary dies from the gases given off by the non-stick surface.
polytetrafluoroethene
Polytetrafluoroethene polymer, PTFE, the monomer tetrafluoroethene, [Repeat unit, -CF2=CF2-],
heat-resistant and chemically inert. Trade names, "Teflon", "Fluon".
Polytrifluorochloroethylene, PTFCE, is similar to PTFE but it can be injection moulded.
Polyprene is used for non-stick surfaces of frying pans and non-lubricated bearings, non-stick
cooking pan lining, gaskets, chemical-resistant films. Polyprene is a thermosetting, thermoplastic
3.7.33 Polytetramethylene ether glycol, PTMEG, low molecular mass, prepolymer used to
fabricate polyurethanes and polyester rubber.
See diagram 16.3.4.10: Polyurethane
3.7.34 Polyurethanes, PUR, (PU), "urethanes", (synthesized by repeating urethane group
(carbamate), -NH-(C=O)-O-
See diagram 16.3.4.10: Polyurethane
Polyurethanes, (some thermosets, thermoplastic, elastomers), synthesized from isocyanates, polyols.
Polyurethanes form tough materials and are used for casting polymer for shaped products, car body
parts, foam rubber, tough linings, paints, rubber, foam plastics, sports articles, furniture, mattresses,
foam insulation in buildings and refrigerators (polyurethane foams), fibres, durable paints, varnishes,
adhesives. Collect, examine and describe different addition polymers. Molecules containing the
isocyanate group, -NCO, can react with molecules containing an -OH group to give a urethane which
is similar to the amide bond in nylons. Heated polyurethanes produce unpleasant vapours that may
contain nitric acid, HNO3, nitrogen dioxide (NO2) and hydrogen cyanide (HCN). So a burning pillow
made of polyurethane foam may produce dense toxic fumes. Polyurethanes can be formulated to make
plastics with either low or high glass transition temperatures for the packaging industry and shoe soles.
3.7.35 Polyvinyl acetal resins, also similar compounds, polyvinyl formal, polyvinyl butyral (PVB),
a polyvinyl ester with ester groups, -CO-O-, replaced by hydroxyl groups, -OH, then acetal groups,
OR1RHOR1.
3.7.36 Polyvinyl acetate
See diagram 3.4.2: Vinyl acetate, polyvinyl acetate (PVA)
Polyvinyl acetate, polyvinylacetate, PVAC (but also called PVA), poly(ethenyl) acetate, PVA but
better would be PVAC so as not to confuse it with polyvinyl alcohol, [C4H6O2, CH2CHCOOCH3],
butan-2-yl acetate, thermoplastic, synthesized by polymerizing vinyl acetate, used in adhesive glues,
wood glue, white glue, school glue, and in carpentry.
Commercial
Adheseal PVA glue, general purpose woodworking glue, 2 litre container, 4 litre container
Polyvinyl alcohol, PVA, PVOH, synthetic polymer, (C2H4O)x, used in adhesives, textile size, synthetic fibres
Order online: Colour changing heat sensitive putty, PVA (polyvinyl alcohol)
3.7.37 Polyvinyl chloride, PVC, polychloroethene, thermoplastic, synthesized from vinyl chloride
[CH2.CHCl]
See 3.5.3: Plastics recycling code, Polyvinyl chloride, 3 V | See 16.14.0: Dioxins, Agent orange,
polyvinyl chloride
Poly(chloroethene), PVC, polyvinyl chloride, (monomer H2C=CHR, where R = -Cl). Polyvinyl chloride
polymer [(CHCl.CH3)n] is made from the monomer is vinyl chloride (chloroethene) [CH2=CHCl]. PVC
is used for artificial leather, building materials, e.g. bottles for mineral water, fruit squash, cooking oil,
shampoo and baby care products, cladding or siding, cable covering, cling film, clothing, flooring, food
packaging trays, furnishings, garden hose, gramophone records, pipes, plastic tubing for burners, plastic
wrap, rain coats, ring binder covers, shampoo containers, sheeting, swimming pool liners, take-out
(take-away) containers, toys, upholstery, vinyl water bottles, wrist watch straps. Polyvinyl chloride
(PVC) is rigid, thermoplastic, impervious to oils and most organic materials, transparent, high impact
strength. PVC may contain and leach to the environment dangerous chemicals, e.g. bisphenol A, cadmium,
dioxins, lead, mercury, phthalates, associated with carcinogens, hormone blockers and other health effects.
3.7.38 Polybenzimidazoles, with aromatic heterocyclic structure, Tg > 400oC
Polyester thermoset resins are formed by polymerization of polyhydric alcohols with polycarboxylic
acids or anhydrides, e.g. starting with maleic acid and fumaric acid with ethylene and propylene alcohol,
polymerized with styrene and reinforced with glass fibres, stiffened with phthalic anhydride, to make
boat hulls, canoes, car body panels.
3.7.39 Polyether ether ketones, PEEK, colourless thermoplastic, have benzene rings linked by
linked by ether (-O-) and ketone (-CO-) groups to form tough flame-resistant thermoplastics in
aerospace construction.
3.7.40 Polyimides, PI, (functional group, -CO-NR-CO- or CO.(N).CO-), thermosetting,
(heat-resistant coatings, flexible cables, electronic circuitry, adhesives), Polypyromellitimide,
 heat-resistant film, trade name "Kapton".
See Imides, imido group: (-CONHCO-), (R1CO-NH-COR2): 16.1.5.8
3.8.1 Silicones, thermoplastic, elastomers, synthesized from silicon, methyl chloride, polymeric
unbranched siloxanes, formula (-OSiR2-)n (R not equal to H) (oil, resins, pastes, casting moulds,
cable sealant, impregnating materials, silicone grease, high vacuum grease, "Volasil" is
octamethylcyclotetrasilocane, the silicone polymer in "Silly Putty" is polyborosiloxane), Silicone
polymer is a generic name for polymers with a siloxane chain.
Silicones: polymeric unbranched siloxanes, Formula: (-OSiR2-)n, (R not equal to H)
3.8.2 Styrenes, styrene (phenylethene, vinylbenzene, ethenylbenzene), colourless, oily liquids
See diagram 16.3.4.2: Styrene, polystyrene
Phenylethene polymerizes to form poly(phenylethene), polystyrene, styrene. Styrenes are used for
"rigid foams", moulded objects, electrical insulation.
3.8.3 SAN, generic name for mixed polymer styrene and acronitrile
(latex paint, plastic plates)
3.8.4 Thermoset plastics
Cross-linking of polymers chains occurs while resins are being moulded resulting in high temperature
stability due to vast network of covalent bonds between the chains. They cannot be melted or recycled
because they are resistant to further heating up to charring point.
3.8.5 Amino-plastics, amino resins, urea-formaldehyde (UF), melamine-formaldehyde (MF), used
in baking enamels with alkyds to increase hardness, colour, and resistance to chemicals.
3.8.6 Aniline-formaldehyde resin
Aniline hydrochloride solution added to aqueous formaldehyde to form red rubber-like polymer.
3.8.7 Epoxy resins, e.g. Araldite, Epon, Hexion
Thermosetting epoxide polymer that cures, i.e. polymerizes and cross-links, when mixed with a hardener.
Usually made from reaction of epichlorohydrin and bisphenol-A.
3.8.8 Glycerol-phthalic anhydride formed by heating phthalic anhydride with equal volume of glycerol
to form a clear plastic. Can also use any oil or fatty acid or some resins.
3.8.9 Melamine-formaldehyde, melamine resin, melamine, made from melamine + formaldehyde,
e.g. Melmac. Used in kitchen bowls and plates but are not microwavable.
3.8.10 Phenolics, phenol resins, phenol-formaldehyde resins, cresol-formaldehyde resins,
melamine-formaldehyde resins, (Formica, electrical insulation, laminates, tableware),
Phenol-formaldehyde resins, "Bakelite" the first polymer, patented 1907, (electric plugs, saucepan
handles), thermoset plastics
3.8.11 Urea-formaldehyde, (urea-methanal) thermoset resin
See diagram 16.3.4.6: Urea-formaldehyde methanal condensation polymerization
See diagram 16.3.4.9: Urea-formaldehyde polymer, melamine-formaldehyde
Urea-formaldehyde resin is thermosetting, has pale colour so it can be dyed, is non-inflammable, and
s used in fibre glass and adhesives. It is sold as a moulding powder with α-cellulose (wood pulp) filler.
These resins are less water-resistant and less heat-resistant than the phenol-formaldehyde resins.
If melamine is substituted for urea, the melamine-formaldehyde resin can withstand temperatures above
100oC and is used for light-coloured dinner ware.
Condensation polymerization with the elimination of water polymer,
(NH2).CO.(NH2) + CH2O ---> NH-CO-NH-CH2 + H2O
urea + formaldehyde ---> urea-formaldehyde
3.8.12 Vulcanized fibre, thermosets, horn-like, synthesized from regenerated cellulose, (suitcases,
gaskets, skis, strengthen wood lamination as sublaminate)
3.8.13 Arcopal crockery
biodegradable plastic
chlorotrifluoroethylene
ebonite (from rubber)
epoxide
isoprene synthetic rubber
3.8.14 Rayon
Rayon polymer, viscose fibre, artificial silk, artificial fibre, Generic name for fibres from regenerated
cellulose
9.1.0 Extrusion
This continuous process is used for the production of semifinished goods such as films, sheet profiles,
tubes and pipes, and sheathing of cables. The goods are “semi-finished” because they must be further
processed before they become useful articles. The thermoplastic raw material for the extruder is
supplied as, a powder or in granule form.
The screw turns in the heated cylinder and forces the material forward while it compacts, plasticizes
(melts) and homogenizes it. A die is placed at the end of the cylinder that moulds the emerging plastic
mass into the desired shape of pipe, sheet or other form.
The operation is, in principle, the same as that of a meat mincer with the addition of heaters in the wall
of the extruder and the length of the deeply cut screw of the extruder is much greater than that of the
mincer screw.
9.2.0 Injection moulding
This process is very widespread because it can produce mouldings of high quality and with great
accuracy, generally without requiring any further work. It is used predominantly for thermoplastics but
smaller amounts of thermosets and elastomers are processed this way.
The injection moulding machine consists of an injection unit and a mould that can be opened. The
injection unit is really an extruder with a screw that can be moved backwards and forwards. It works
by plasticizing the material as the screw rotates and moves backwards and then forces the molten
material out into the mould as the screw is driven forward.
Injection moulding machine
The mould is closed and its cavities are filled with the molten plastic injected by the screw.
Feed
Plasticisation
Drive
Injection and cooling under pressure
Ejection
9.3.0 Blow moulding
The process is used for moulding hollow articles in thermoplastics. An extruder forces the plastic tube
vertically downwards between the two halves of an open two part mould. The closing of the mould
squeezes an air-tight seal at the top and the bottom, then compressed air is blown into the plastic tube
forcing out against the wall of the mould cavity while it cools. to form a hollow article, e.g. a bottle.
9.4.0 Rotational moulding
This process is simple in concept. Heat is used to melt and fuse a plastic resin in a closed mould. No
pressure is involved. The three stage process includes loading the resin in the mould, heating and fusion
of the resin and cooling and unloading the mould. After the charged mould is placed in an oven, the
mould is rotated on two axes at low speed. As heat penetrates the mould the resin adheres to the inner
surface until it is completely fused. The mould is then cooled by air or water spray, or a combination of
both, while still rotating, lowering the temperature gradually. The mould is opened, the finished part
removed and the mould is recharged for the next cycle. Rotationally moulded products include shipping
drums, storage tanks and receptacles, material handling bins and fuel tanks. Consumer products include
furniture, light shades, toys, surfboards and marine accessories.
9.5.0 Calendering
The calender produces semi-finished goods in sheet form. Applications include brief cases and school
 satchels, awnings, coverings, occupational protective and warning clothing stationery files, wrappings,
pouches, upholstery. They are also used in car interiors, children's and doll's prams, decorative sheeting,
light fittings, wallpaper, and flooring sheeting for garden furniture.
The most important application of this process is in the production of PVC sheeting and in the coating of
fabric. Plastics which melt to a rather low viscosity (as for example polyethylene) are not suitable for
calendering.
Polyvinyl chloride is continuously rolled as a semi-molten plastic between two or more rollers to give an
 endless sheet. After leaving the calender, the sheet, which can be embossed during the calendering
process, can be metallized, printed or surfaced with flock by means of appropriate treatments.
The working principle involved here is similar to that of the old-fashioned kitchen mangle.
Running sheet on the calender.
Plasticized mass
heated rolls
sheet
9.6.0 Foaming
See diagram 16.3.4.10: Polyurethane
The inclusion of air or gases in the structure of foamed materials reduces their density..
One method involves mixing compressed air or gas into the plastic mass, and on subsequent processing
the gas is liberated and forms a foam. In another important method a 'blowing agent' such as sodium
bicarbonate is added to the plastic raw materials. When the hot melt is formed the sodium bicarbonate
decomposes, giving off carbon dioxide gas which forms bubbles in the foam. The bubbles are fixed on
solidification and they confer a light density on the material.
Recently, foamed materials have become more and more important in trade and industry, not least
because so many polymers can be expanded in the ways mentioned. They include polyethylene, polystyrene,
polyvinyl chloride (PVC), phenolic, urea, epoxide, polyester, and polyurethanes in rigid and flexible forms.
Plastics foams can be manufactured not only by special methods but also by injection moulding, extrusion
and calendering.