Polymer chemistry-plastics
Polymers consist of repeating units known as monomers or ‘mers’. Polymers are giant molecules with a carbon chain backbone. A common polymer in engineering is pvc. Its monomer is ethylene chloride.
There are two main categories of polymers:
Thermoplastics and Thermosets
Thermoplastics-these polymers become plastic at high temperatures and con be moulded or drawn into fibres.
- Can be injected into a mould
- Can be remelted can be remoulded
- Easily fabricated
- Ductile
- Easily drown into fibres
Examples in clued Perspex and PVC
Thermosets –these polymers cannot be re softened by heating. Once they are formed heat cannot reshape it they have rigidity. Examples include Bakelite and epoxy resin.
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