Chapter 4 Biomedical elastomers

Abstract

Elastomers are described as materials that possess pronounced elasticity and rebound. They can be tough, relatively impermeable to air and water and exhibit resistance to cutting, tearing and abrasion. Often they are modified by compounding to increase their hardness and strength. Or, conversely, they can be soft, compliant and absorbent to water if the need exists. In some instances their properties can closely simulate that of the tissues which they must contact. As biomedical materials they may have originated from commercial formulations or been custom designed from basic chemistry. Those that have been judged as biocompatible have made significant contributions towards the development of successful medical devices. Literally, every basic elastomer has been evaluated at some time for its possible suitability in contact with the body. This would include such materials as natural rubber, styrene rubber, polybutyl rubber, silicone rubber, acrylate rubber, Hypalon®, polyurethanes, fluorinated hydrocarbon rubbers, polyvinyl chloride, thermoplastic vulcanizates and others. Of these, only special medical grade formulations of silicone, polyurethane, polyvinyl chloride and thermoplastic elastomer have continued to be commercially successful.