The best way to prepare TPVs is by melt-mixing of a semi-crystalline thermoplastic and a rubber, followed by the simultaneous vulcanisation of the rubber phase during mixing. The crosslinking of the rubber phase during melt-blending with the thermoplastic is called dynamic vulcanisation. The original investigations on the dynamic vulcanisation of TPVs were performed on polypropylene and different rubber compositions, and were initiated by Fisher [3] and Coran et al. [4]. A well-known commercial example of dynamically vulcanised thermoplastic-elastomer compositions are blends of polypropylene (PP) and ethylene–polypropylene–diene terpolymer rubber (EPDM) [2]. These TPVs are prepared by first melt-mixing PP with EPDM whereby a co-continuous phase morphology is formed. Subsequently a vulcanisation agent (peroxide or phenolic resin) is added to crosslink the EPDM rubber phase, and hereby the rubber phase is not able anymore to coalesce into a continuous phase. At the end of the melt-mixing process, the rubber phase will be finely dispersed in the thermoplastic matrix. The phase morphology formation in dynamically vulcanised PP/EPDM blends has been examined in detail by Radusch et al. [5].