New Developments in Dynamically Cured PP—EPDM Blends

Abstract

Abstract Different procedures for preparing thermoplastic vulcanizates (TPVs), based on isotactic polypropylene (iPP) and ethylene—propylene—diene terpolymer rubber (EPDM), are used and analyzed in this work. In order to determine the effect of the vulcanization method on material properties, a rheological study, dynamic-mechanical analysis, mechanical properties and morphological study have been carried out. In all cases, the sulfur is used as crosslinking agent of the elastomeric phase. It has been shown that the dynamically cured blends (referred in the work as V2 and V3) present better properties in relation to those statically cured (V1) and uncrosslinked (V). Thus, the elastic ability, mechanical properties and rheological characteristics of these systems sensibly increase when the samples are dynamically vulcanized. Morphological analysis performed by scanning electron microscopy (SEM) is clearly in agreement with the analyzed properties, showing a better dispersion between both polymeric chains, when the blends are dynamically cured. These results seem to indicate that the dynamic vulcanization process gives rise to the formation of a thermally stable three-dimensional network, and as a consequence of it, a sensible increase of the properties is obtained.