WHITE RICE HUSK ASH FILLED ETHYLENE-PROPYLENE-DIENE TERPOLYMER/POLYPROPYLENE BLENDS: EFFECT OF DYNAMIC VULCANIZATION AND FILLER LOADING

Abstract

The effect of dynamic vulcanization and influence of filler loading of white rice husk ash filled elastomer rich ethylenepropylene diene terpolymer and propylene blends were investigated. Blends with filler loading ranging from 0 to 60 php (Parts per hundred of total polymer by weight) were prepared in a Brabender plasticorder at 180°C and a rotor speed of 50 rpm followed by compression molding. The Brabender torque was used to investigate mixing progress. The mechanical properties of vulcanized blend systems were compared with those of the unvulcanized counterparts. The mechanical properties of the blends as a function of filler loading were also studied for both blend systems. Processability and recyclability of the blends were carried out to assess the thermoplastic characteristics of the blends. Brabender torque studies showed that dynamic vulcanization has a more significant effect on melt rheology than filler loading. It was also found that unvulcanized blends exhibited poor tensile properties, low hardness and high compression set. However, dynamically vulcanized blends exhibit mechanical properties, which are superior to those of unvulcanized blends. As filler loading increases, the hardness of the blends slightly increases whereas tensile properties, tear strength, and compression set deteriorates. Processability and the possibility of recycling of dynamically vulcanized blends with high elongation and low compression set indicate that dynamic vulcanization confers thermoplastic elastomeric properties to the blends. The study further revealed that white rice husk ash filled blends can also be dynamically vulcanized to achieve enhanced properties in a similar manner to the unfilled blends.