Polymers Flashcards
What are polymers?
Organic material made up of chain of single units called monomers
What are the two main sources of polymers?
- Synthetic polymers
- Natural polymers
What are synthetic polymers?
Commonly used
Chemically manufactured from carbon-based materials such as crude oil
What are natural polymers?
Processing natural materials e.g plants
latex from trees
What are the two main types of polymer
- Thermosetting plastic
- Thermoplastic polymers
Properties of poylmers
- Lower density of metals
- Not normally painted but painted pigment to them
What are thermosets formed by?
Moulding process
Why are thermosetting plastic harder than thermoplastics?
During the process of making
form many links across different polymer chains
stop movement of chains
General properties of thermosetting plastic
- good resistance to electricity and heat
What happens after thermosetting plastics are moulded?
They cannot be re-shaped
Thermosetting plastic
What is melamine formaldehyde used for?
- Impact-resistance plastic plates
- laminate covering for kitchen workshops
- cupboards
- moulding for electrical equipment
- light fittings
Thermosetting plastic
What is phenol formaldehyde?
A dark coloured brittle plastic
Thermosetting plastic
What is phenol formaldehyde used for?
- Electrical fittings e.g light sockets
- Heat -resistant parts for domestic appliances e.g handles for cookers and pans
Thermosetting plastics
What is urea formaldehyde used for?
- Coloured with artificial pigments
- Used to make electrical fittings e.g light switches
Thermosetting plastic
Epoxy resin: what is it used for?
PCB
‘cold cast’ electrical insulators
