1. P l a s t I c s By: Alison Luk Beatrix Lee Sally Campbell

2. Bonds in Plastics Covalent Bond Atoms share electrons in outer shell Strongest type of bonding Primary bonds in plastics

3. Thermosets and Thermoplastics Macromolecules – long chains of molecules Secondary bonds – weak forces of attraction Thermoplastic Primary bonds – strong forces of attraction Thermosetting plastic

4. Elasticity in thermoplastics Weaker secondary bonds enable elasticity When under load within elastic limit, plastic can return to original form When load exceeds elastic limit, plastic deforms Some plastics also suffer from creep

5. Heating thermosets and thermoplastics Recyclable

6. Properties of Plastics Stronger More brittle Low tensile elongation Low viscosity (in liquid form) Higher temperature resistance Tougher (more impact strength) Less brittle High tensile elongation High viscosity (when liquid) Thermosetting plastic Thermoplastic

7. Chemical-resistant containers e.g. Food Containers Hinges Polypropene/Polypropylene Fishing nets Bottle crates Medical equipmente.g. syringes

8. HDPE: Bottles Pipes Bowls Milk Crates Buckets Polyethene/Polyethylene LDPE: Packaging film Carrier bags TV cable Toys Detergent 'squeezy' bottles

9. Varnish Cushioning & buoys in boat hulls Skateboard wheels Polyurethane(can be thermoplastic or thermoset) Shoe soles Artificial sponges

10. Textiles i.e. clothing Electrical fittings i.e. plugs Wood adhesives Urea-Formaldehyde

12. Non biodegradable

14. Plastic Resin Symbol

15. easily distinguished

16. faster recycling process