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Plastics
Info on plastics
| Question | Answer |
|---|---|
| What are the two types of plastics? | Thermoplastics Thermosetting plastics |
| Can thermosetting plastics melted again into a new product? | No |
| Can thermoplastics be melted again into a new product? | Yes |
| Why can't thermosetting plastics be remoulded? | Have strong permanent cross-links between the polymer chains which heat is unable to break. |
| Why can thermoplastics be remoulded? | Have weak temporary cross-links between the polymer chains which heat is able to break. |
| Polymerisation: | All plastics come from taking a monomer and joining it to lots of others to make a chain. This is a polymer. |
| Are plastics renewable or non-renewable? | Non-renewable. Someday they will run out. |
| Name three examples of thermosetting plastics | 1. Urea Formaldehyde 2. Melamine Formaldehyde 3. Epoxy Resin |
| Properties of Urea Formaldehyde | 1. Heat resistant 2. Scratch resistant 3. electrical insulator |
| Properties of Melamine Formaldehyde | 1. Hard 2. Scratch and stain resistant |
| Properties of Epoxy Resin | 1. Hard 2. electrical insulator 3. chemical resistant to wear and tear. |
| Uses of Urea Formaldehyde | Electrical fittings: E.g. plus sockets. |
| Uses of Melamine Formaldehyde | Plastic cups and plates and other tableware. |
| Uses of Epoxy Resin | Araldite adhesive |
| Name three examples of Thermoplastics | 1. Acrylic 2. PVC (Rigid) 3. PET |
| Properties of Acrylic | 1. transparent (see through) 2. impact resistant 3. can be blow moulded |
| Properties of PVC (Rigid) | 1. UV light resistant 2. flammable 3. can be injection moulded |
| Properties of PET | 1. stiff 2. chemical resistant 3. can be blow moulded |
| Uses of Acrylic | 1. Signs 2. baths 2. car lights |
| Uses of PVC (Rigid) | 1. pipes (plumbing) 2. shoe soles 3. floor/wall coverings |
| Uses of PET | 1. Bottles for up to 2 litres capacity |