Abstract

Thermoplastic elastomers have many of the physical properties of vulcanized rubbers but can be processed as thermoplastics. This unique behavior has opened a new field of polymer science and technology. Since their commercial introduction in the 1960s, thermoplastic elastomers have become a significant part of the polymer industry. They are used in applications as diverse as adhesives, footwear, medical devices, automobile parts, and asphalt modification. Many of them are block copolymers with alternating hard and soft segments. The thermoplastic elastomers with polystyrene hard segments are the larget group and probably the most versatile; they can be produced over a wide range of hardness values and applied either in the molten state or from solution. Other examples are block copolymers with elastomers, either vulcanized or unvulcanized, in which the two components are intimately mixed together, but in most cases still remain as separate phases. Thermoplastic elastomers of this type are generally used as replacements for vulcanized rubbers. This article reviews the synthesis, morphology, structure–property relationships, and commercial applications of thermoplastic elastomers of all types.