Motor car wheel hub cover, 1990s.
© Science Museum / Science & Society Picture Library
A wheel hub cover made of ABS (acrylonitrile butadiene styrene). ABS is a thermoplastic copolymer made by combining acrylonitrile with butadiene and styrene. Polymers, are large molecules formed from chains of repeating simple molecular sub-units known as monomers. A copolymer is a polymer made by adding monomers of two or more different chemicals together. The properties of the final material can be altered by varying the relative proportions of the constituent monomers. ABS has a low density, but is very hard, making it highly suitable for manufacturing objects such as telephones, computer bodies and car body panels.