Effect of dynamic vulcanization on PP/EPDM composite

Abstract

Many papers are involved with the mechanical and electrical properties of rubber or composites cured in traditional way but few involve the properties of dynamically vulcanized composites. The effect of dynamic vulcanization on mechanical and electrical properties of a PP/EPDM composite was studied in our laboratory. The relationship between the mechanical properties of the composite and the vulcanizator concentration and ratio of PP/EPDM is presented. As the ratio of PP/EPDM increases, the tensile strength increases and elongation decreases. When vulcanizator content is about 1.2 by weight percent both mechanical and electrical properties reach optimal values. In order to understand the dependence of mechanical properties on vulcanization concentration and PP/EPDM ratio, scanning electronic microscopy (SEM) is used to examine the micro-morphology of the composite. From the SEM photograph it can be seen that the mechanical properties of the composite depend on the uniform distribution of the rubber particle in a PP matrix. Obviously, dynamic vulcanization contributes to the formation of small particles and an improvement of compatibility between PP and EPDM. Therefore the PP/EPDM composite possesses good mechanical properties. The electrical properties, insulation resistivity and dielectric loss factor (tan/spl delta/), of the composite with improved mechanical properties were also measured. Therefore dynamic vulcanization improves the mechanical and electrical properties of the PP/EPDM composite.