Book excerpt: Thermoplastic elastomers (TPEs) have the elastic behaviour of rubber and the processability of thermoplastics. The Freedonia Group has forecast that demand will expand by 6.4% per year to around 2.15 million tons in 2006. There is potential for these new, exciting materials to expand into the much larger thermoset rubber markets. This review includes comparisons between the two material types. There are three major types of TPE: block copolymers, rubber/plastic blends and dynamically vulcanised rubber/plastic alloys known as thermoplastic vulcanisates. The chemistry of these materials and how.