The list of synthetic polymers roughly in order of worldwide demand, includes polyethylene, polypropylene, polystyrene, polyvinil chloride, and many more.

More than 330 million tons of these polymers are made every year (2015).

A simple example is polyethylene (‘polythene’ in British English), whose repeat unit or monomer is ethylene.

Nowadays, synthetic polymers are used in almost all walks of life. Modern society would look very different without them. The spreading of polymer use is connected to their unique properties: low density, low cost, good thermal/electrical insulation properties, high resistance to corrosion, low-energy demanding polymer manufacture and facile processing into final products. For a given application, the properties of a polymer can be tuned or enhanced by combination with other materials, as in composites.

Their application allows to save energy (lighter cars and planes, thermally insulated buildings), protect food and drinking water (packaging), save land and lower use of fertilizers (synthetic fibres), preserve other materials (coatings), protect and save lives (hygiene, medical applications).