Influence of different mixing sequence on UHMW‐EPDM based thermoplastic vulcanizates: Mechanical, rheological and morphological characteristics

Abstract

AbstractAn important factor for the preparation of thermoplastic vulcanizates (TPVs) is the mixing sequence or technique as it is controlling the product quality and production rate. The effect of different routes of mixing sequences on the mechanical properties and rheological properties have been studied. Four different types of mixing sequences have been pursued and ultra‐high molecular weight EPDM (UHMW‐EPDM) master batch technique has shown maximum prospect over the melt blending method. Co‐agent master‐batch sample showed optimum balance between TS and %EB over the other master‐batch samples. Melt blending technique shows moderate properties for all cases. Rheological data follows the same trend as observed for the mechanical properties. Crosslink density also found the highest for the co‐agent master‐batch sample and co‐agent/peroxide master‐batch sample over the other two samples. Cryo‐fractured and etched TPV samples were prepared and examined in FE‐SEM. Co‐agent master‐batch sample shows the droplet type morphology. This new type of UHMW‐EPDM based TPV with co‐agent/rubber master‐batch mixing technique leads to superior physico‐mechanical properties over the other mixing techniques. These newly established TPVs can be used as various injection molded parts, esthetic seals/strips and 2K‐molds for the automotive applications.