1. Plastics and Synthetic Fibres Topic 13

2. Synthetic Fibres Many items of clothing contain materials such as polyester, polyamide, terylene, rayon, dralon etc. The items previously mentioned are all man-made fibres, and are called synthetic fibres.

3. Origin of Plastics Crude oil is used to make plastics and synthetic fibres. Long chain hydrocarbons can be cracked or broken into a mixture of short chain hydrocarbons, some of which are saturated and others unsaturated.

4. Properties of Plastics PlasticsUsesProperties Poly(ethene)Plastic bagsStrong, light, waterproof PolyamideBlouses, tightsHard wearing PolyesterShirts, blouses, quilts Wears well, helps keep shape of clothing, warm Bakelite Pot handles, electrical sockets Does not melt or conduct heat or electricity RubberSoles of shoes, tyresFlexible, waterproof DralonFurniture covers Hard wearing, stain resistant

5. Uses of Natural and synthetic fibres Fibre Natural / Man-made Origin CottonNaturalCotton plant PolyamideSyntheticCrude oil PolyesterSyntheticCrude oil SilkNaturalSilk worm ViscoseSynthetic Cotton plant after treatment WoolNaturalSheep

6. Advantages and disadvantages of plastics PlasticAdvantagesDisadvantages Poly(ethene)Cheap, waterproofDoes not rot away Melamine/FormicaHeat resistant Not as attractive as wood Polyurethane foam Makes cheap seating Gives toxic fumes when burned Polystyrene Makes protective TV cases Made from crude oil which is a finite resource Silk (Natural)More attractiveMore expensive

7. Natural fibres such as silk, cotton, wood and paper are more likely to be BIODEGRADABLE (will break down naturally)