Studies of in-situ Compatibilized Blend of Silicone and EPDM Rubbers

Abstract

Abstract The effect of three different compatibilizers — ethylene methylacrylate copolymer (EMA), ethylene vinyl acetate copolymer (EVA), and silane grafted polyethylene (VMX) — on the physical properties, ageing behavior, thermal stability, morphology, and dynamic mechanical properties of a 50/50 blend of silicone/EPDM has been studied. Improvement in physical properties is in line with the level of technological compatibilization. Strength of adhesion for silicone-EPDM joints is significantly enhanced by the compatibilizers due to the increase in surface energy of silicone and reaction of the rubbers with the compatibilizers. Morphology study shows smaller domain size for the compatibilized blend. Dynamic mechanical analysis also reflects strong interaction of the compatibilizer with the blend components. Ageing properties are improved with the addition of the compatibilizers. Thermogravimetric analysis indicates an increase in activation energy of degradation and hence marked improvement in the thermal stability of the blends containing compatibilizer.