Plastics and Synthetic Fibres

1. Plastics and Synthetic Fibres Intermediate 2 Chemistry Unit 2(d)

2. Examples of plastics

3. Examples of plastics • Polythene [poly(ethene)] • Polystyrene • Perspex • PVC • Nylon • Bakelite • Formica • Silicones

4. PVC [poly(vinyl chloride)]

5. Nylon

6. Bakelite

7. Formica

8. Silicones

9. Where do plastics come from? • Crude oil • Fractional distillation • Cracking • Alkenes

10. Uses related to properties • Flexible • Watertight • Shatter-proof • Light

11. Non-biodegradable • Can’t be broken down by living things. • “Biopol” is a recently developed biodegradable plastic.

12. Other problems with plastics • Low density • Durable • Burn or smoulder to give off toxic fumes • Carbon monoxide • Hydrogen chloride • Hydrogen cyanide

13. Types of plastic • Thermoplastic • Can be reshaped on heating • Thermosetting plastic • Cannot be reshaped on heating

14. Chemistry of plastics • Plastics are examples of polymers • These are long chain molecules made from smaller molecules joining together • These smaller molecules are called monomers • There are two types of polymer: • Addition polymer • Condensation polymer

15. Addition polymers

16. Addition polymers • Like all polymers, these are made from monomers. • For an addition polymer, these monomers always have a C=C • These join together in a reaction called addition polymerisation. • view animation

17. 1 2 3 … … + + … … 1 2 3 MONOMERS POLYMERS

18. 1 3 2 3 1 2 + + … … MONOMERS POLYMERS

20. Naming polymers • The name of the polymer is made by taking the name of the monomer, putting brackets around it, and adding “poly” in front • Poly(ethene) is made from ethene; • Poly(vinyl chloride) is made from vinyl chloride.

21. Naming practice • Name the polymer made from: • Propene • Chloroethene • Name the monomer used to make: • Poly(heptene) • Poly(phenylethene)

22. Drawing polymers, monomers and the repeating unit

23. C=C H H H H H H C6H5 H C6H5 H C6H5 H Poly(phenylethene)

25. Condensation polymers

26. What type of molecule is produced from an alkanol and alkanoic acid? • Esters • Polyesters are made from similar molecules.

27. Polyesters

28. Monomers • Must have two functional groups per molecule • For polyesters, they are a diol and a diacid

29. Condensation polymerisation • The joining up of two molecules, producing water, is condensation. • Because giant molecules are made, this is condensation polymerisation. • Specifically with a diol and a diacid, a polyester is produced.

30. Polyamides • Are produced when an amine group reacts with a carboxyl group.

32. An AMIDE group Amides • Formed when an amine reacts with an alkanoic acid. amide amine carboxylic acid

33. Polyamides • Are condensation polymers. • Formed when a diamine reacts with a diacid.

34. Recently developed plastics • Kevlar • Very strong • Poly(ethenol) • Water soluble • Biopol • Biodegradable

35. Kevlar

36. Kevlar

37. Poly(ethenol)

38. Poly(ethenol)