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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 |