What are plastics?

Plastics are the most widely used material in commercial production. Plastics can be created from two main sources which are natural and synthetic materials.

Source one - Natural plastics: include amber which is fossilised tree resin, latex which is a form of rubber.

Amber which is fossilised tree resin		Rubber being drained from a rubber tree

Source one - Synthetic plastics: are chemically manufactured from carbon based materials such as crude oil, coal and gas.

Crude oil works		A piece of coal

How are plastics made?

Plastics are produced using a process know as polymerisation. Polymerisation occurs when monomers join together to form long chains of molecules called polymers.

Polymerisation comes from the word 'POLY' which means 'MANY' and 'MER' which means 'PART'. So Polystyrene means 'POLY' many single monomers of 'STYRENE', joined together to form a long chain.

What groups of plastics exist?

There are two main groups of plastic which are thermosetting plastics and thermoplastics.

Thermoplastics

Thermoplastics can be heated and shaped many times. Thermoplastics will soften when it is heated and can be shaped when hot. The plastic will harden when cooled, but can be reshaped because their is no links between the polymer chains. Some common thermoplastics are ABS (acrylonitrile butadienestyrene), Nylon (polyamide), acrylic (polymethyl methacrylate), uPVC (polyvinyl chloride), polystyrene, polypropylene and cellulose acetate.

Thermosetting plastics

Thermosetting plastics can only be heated and shaped once. If re-heated they cannot soften as polymer chains are interlinked. Separate polymers are joined in order to form a huge polymer. The main thermosetting plastics are epoxy resin, melamine formaldehyde, polyester resin and urea formaldehyde.