Plastics

Properties of polymer depend on nature of
monomers and the way they are related each to others.
Plastics can be classified in two categories according to
their reactions to heat.

	When thermoplastics are heated, they become malleable and pasty. While cooling, they solidifie and can be molten again. These polymers represent 80% of the world market of plastics. The processing speed and the reuse possibility of production waste supported their employment.
Thermoplastics

The shape obtained by heating a thermosetting plastics is irreversible. This kind of plastics represent 20% of the world market of plastics. They are able to withstand temperatures higher than thermoplastic ones but their process is slower.
	Thermosettings