Abstract
In this paper were investigated influences of various types and concentrations of crosslinking agents on the properties of thermoplastic vulcanizates based on ethylene-propylene terpolymer rubber (EPDM) and plasticized poly (vinyl chloride) (PVC). Three different crosslinking systems were used: (a) common method with sulphur and vulcanization accelerators (tetramethylthiuram disulfide and mercaptobenzothiazole); (b) crosslinking with di(tert-buthyl peroxi-isopropyl) benzene Perkadox 14-40B-GR and co-agent trimethylol-propane trimethacrylate TMPT DL 75 (c) vulcanization with phenol resin Ribetak 75-30E and tin chloride dehydrate. The influence of each crosslinking systems on cross-link density, mechanical properties and DSC analysis of samples were investigated. The hardness shows a slight decrease as a result of dynamic vulcanization, because this is a way to disperse large amounts of elastomer in the thermoplastic matrix, resulting in a refined morphology. It was observed that the highest values of crosslinking density and 100% modulus were obtained by using the classic cross-linking with sulphur and accelerators, and that for a reduced amount of crosslinking agents used, there was a decrease in crosslinking density. Elastomer crosslinking led to an increased Tg and decreased Tm. These blends can be used in the manufacture of hoses, gaskets, footwear constituents etc. Keywords: TPV, EPDM, PVC, cross-link density, differential scanning calorimetry