Publisher Summary There have been major developments in three areas where the author has considered it more useful to review the different polymers together, namely thermoplastic elastomers, biodegradable plastics, and electrically conductive polymers. All the three types of material have now been available for some years, and it is probably also true that none have yet realized their early promise. In the case of the thermoplastic elastomers, most of the commercial materials are processed on more or less standard thermoplastics processing equipment, but they have also become established in applications more in competition with conventional thermoplastics rather than with rubbers. The concept of degradable polymers arose largely from concern about the large quantities of plastics materials used for packaging and which, having fulfilled their function, were then discarded and unwanted. Electrically conductive polymers are just one of a number of esoteric possible uses for synthetic polymers. These materials are now being considered for a variety of applications. Cellulose films are biodegradable, that is, they are readily attacked by bacteria, films, and packaging from synthetic polymers are normally attacked at a very low rate. This has led to methods of degrading polymers to a sufficiently low molecular mass that are then accessible to biodegradation.