Thermoplastic vulcanisates (TPVs) are a relatively new class of materials, which combine the excellent processing characteristics of thermoplastics with the elastic properties of elastomers. The elastic properties of this type of blends are similar to the more conventional class of thermoplastic elastomers based on hard segment and soft segment block copolymers [1] and [2]. The ideal morphology is a fine dispersion of the elastomer in a relatively small amount of the thermoplastic polymer. The dispersed elastomer particles have to be crosslinked in order to promote elasticity.