PHYSICO - MECHANICAL PROPERTIES OF NBR/SBR BLENDS

Abstract

Three compatibilizing agents (maleic anhydride, styrene maleic anhydride and styrene butyl acrylate) have been added to NBR/SBR blends to improve the phase morphology and interfacial adhesion, thereby improving the physical & mechanical properties of the blend. The physico-mechanical properties such as rheological properties, tensile stress and sorption properties were examined, for different formulae of NBR/SBR blends. The sorption of toluene into noncompatibilized NBR/SBR blends was studied. Pure SBR and 50/50 blend NBR/SBR showed the minimum sorption and the highest mechanical properties. Three different compatibilizers where added at a different levels to 50/50 NBR/SBR blend and their effect on swelling diffusion coefficient, transport mechanism, tensile stress and elongation at break were studied. It observed that the rheological properties are not affected with the kind of compatibilizer or its doses. the best value of tensile strength and elongation percentage at the break can be obtained when add 0.6 phr of maleic anhydride, 4 phr of styrene maleic anhydride and 4 phr of styrene butyl acrylate as a compatibilizer with NBR/SBR 50/50. Less sorption of toluene is showed with high amount of maleic anhydride or styrene maleic anhydride as a compatibilizer, and also when used butyl acrylate as a compatibilizer at 2 phr. Diffusivity reduced at the higher doses of either maleic anhydride or styrene maleic anhydride in the blend and it increased at a dose of 6 phr of styrene butyl acrylate as a compatibilizer.