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27 Cards in this Set
- Front
- Back
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Natural polymers |
Proteins, cellulose, starch, some resins and rubber |
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Semi synthetic polymers |
Cellulose derivatives as cellulose acetate (rayon) and cellulose nitrate |
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Synthetic polymers |
Plastic (polythene), synthetic fibres (nylon 6,6) and synthetic rubber (buna-s) |
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4 major industries of polymers |
Plastics, elastomers, fibres and paints and varnishes |
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Addition polymers |
Polythene, teflon, polyacrylonitrile and rubbers |
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Condensation polymers |
Polyamides, polyesters, phenol-formaldehyde polymer and melamine-formaldehyde polymer |
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Low density polythene |
1000-2000 atm, 350-570k, presence of traces of dioxygen or a peroxide initiator (catalyst) Obtained through free radical addition and H-atom abstraction |
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High density polythene |
6-7 atm, 333-343k, in a hydrocarbon solvent in the presence of a catalyst like triethylaluminium and titanium tetrachloride (Ziegler Natta catalyst) |
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Polytetrafluoroethene (Teflon) |
Heating with free radical or persulphate catalyst at high pressure Used to make oil seals, gaskets and non-stick surface coated utensils |
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Polyacrylonitrile |
Addition rxn in presence of peroxide catalyst Used as substitute for wool in making commercial fibres as orlon or acrilan |
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Nylon 6, 6 |
Condensation polymerisation of hexamethylenediamine with adipic acid under high temp and high pressure Fibre forming solid, high tensile strength, H-bonding thus crystalline nature Used in making sheets, bristles for brushes and in the textile industry |
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Nylon 6 |
Heating caprolactum with water at high temperature (533-543k)
Used to make tyre cords, fabrics and ropes |
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Polyesters |
Dicarboxylic acid + diols
Dacron/terylene = ethylene glycol + terephthalic acid, 420-460k, in presence of zinc acetate-antimony trioxide catalyst
Dacron fibre is crease resistant and used in blending with cotton and wool fibres, and also as glass reinforcement in safety helmets |
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Phenol- formaldehyde polymer |
Oldest synthetic polymers Presence of either base or acid catalyst Initial product = linear, novolac - used in paints Novolac on heating with formaldehyde undergoes cross linking giving infusible solid mass - Bakelite Bakelite makes combs, phonograph records, electrical switches and handles of utensils |
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Melamine - formaldehyde polymer |
Resin intermediate is present Used to make unbreakable crockery |
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Butadiene - Styrene |
Copolymer A good substitute for natural rubber
Makes autotyres, floor tiles, footwear components and cable insulation |
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Natural rubber |
Made from rubber latex which is a colloidal dispersion of rubber in water. Rubber tree: India, Srilanka, Indonesia, Malaysia and South America Linear polymer of isoprene (2-methyl-1, 3-butadiene) aka cis - 1, 4- polyisoprene Coiled structure cuz van der Waals force |
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Vulcanisation of rubber |
Soft > 335k. Brittle < 283k. Heating of raw rubber and an appropriate additive at 373-415k, sulphur forms cross links and this gets stiffened For tyre rubber, 5% of sulphur is used as crosslinking agent |
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Neoprene |
Aka polychloroprene Free radical polymerization of chloroprene Superior resistance to vegetable and mineral oils. It is used to make conveyor belts, gaskets and hoses. |
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Buna - N |
1, 3 butadiene and acrylonitrile in the presence of a peroxide catalyst. Resistant to the action of petrol, lubricating oil and organic solvents. Used to make oil seals and tank lining. |
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PHBV |
3 - hydroxybutanoic acid and 3 - hydroxypentanoic acid. Polyester
Used in speciality packaging, orthopaedic devices and in controlled release of drugs.
Undergoes bacterial degradation in the environment. |
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Nylon 2 - nylon 6 |
Glycine and amino caproic acid |
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Polypropene |
Manufacture of ropes, toys, pipes and fibres |
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Polystyrene |
An insulator, wrapping material, manufacture of toys, radio and television cabinets |
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Polyvinyl chloride PVC |
Manufacture of rain coats, handbags, vinyl flooring and water pipes |
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Urea - formaldehyde resin |
Makes unbreakable cups and laminated sheets. |
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Glyptal |
Manufacture of paints and laquers. |
