Recent developments for thermoplastic elastomers

Abstract

In this paper, we review a number of the latest developments for the broad family of thermoplastic elastomers (TPEs); these can be seen mainly in the groups of block copolymers and polymer blends, including dynamically vulcanized polyblends. Recently, the synthesis and properties of TPEs derived from triazinedithiols, which have been considered promising components for hard segments, have been reported. Polyesteramide elastomers based on terephthalamide hard segments of uniform length with various soft segments exhibit excellent thermomechanical properties that make them effective in applications like automotive parts and industrial parts that demand a wide service temperature range and oil resistance. Other novel TPEs based on polyurethane/poly(methylmethacrylate-co-styrene) semiinterpenetrating polymer networks were synthesized using a simultaneous interpenetrating networks technique. Their morphology is similar to that of dynamically vulcanized TPEs. Blended TPEs, in which the plastic phase is represented by polyvinylchloride (PVC), have been commercialized. Also, there is some research on the dynamically vulcanized blends of PVC with chloroprene rubber (CR). A disadvantage can be seen in the finding that CR/PVC blends are liable to undergo thermo-co-cross-linking; thus, problems in their recycling can be expected. Thermoplastics and rubbers are not only mixed together to obtain blended TPEs, but also are mixed with other TPEs, as well as the TPEs being mixed together to improve their properties. A commercial line of TPEs utilizes proprietary vulcanization technology to achieve a broad property profile. Thus, secondary modification of TPEs is of growing importance.