ABSTRACT

The classification of polymers with backbones containing atoms other than aliphatic carbon calls for some arbitrary decisions. Ester, ether, and amide groups in the main chain distinguish some classes. However, polymers based on isocyanate or aldehyde reactions may contain a variety of groups, especially when network structures are produced. The silicones and phosphazenes form distinct families, at least in their commercial applications. Finally, this chapter concludes with brief summaries of two industrial categories based on physical properties rather than chemical composition. As the name implies, high-performance polymers (including both thermoplastic and thermoset materials) are usable at elevated temperatures. The other category is that of thermoplastic elastomers, which have rubbery properties at room temperature. Natural heterochain polymers such as cellulose-based polysaccharides, plant and animal polyesters, and proteins (polyamides) are discussed in Chapter 15.