ABSTRACT
The specification of polymers relates directly to their properties. As the numbers of polymers are so large it is worthwhile to draw up a checklist of desirable properties needed when specifying a polymer, arriving at a performance specification. The Identification of plastics kit produced by Building Research Station gives a number of simple tests that can be used to identify plastics. Environmental stress cracking is accepted as a term for embrittlement that is caused by the use of abrasive cleaners and chiefly organic chemical agents and gases. It is the energy obtained from ultraviolet light that alters the chemical bonding of polymers by causing chain scission, oxidation, cross-linking, hardening and subsequent embrittlement. Small hairline cracks will also give an uneven reflection of light back from the material surface, and this leads to an apparent colour loss. It is important that polymers are also used in situations where their absorption of water is not a problem.
