ELASTOMER NETWORKS BLENDS : MECHANICAL AND DYNAMIC MECHANICAL CHARACTERISATION

An initial study of hydrothermally weathered specimens of silicone rubber, EPDM rubber, and 50:50 weight ratio blend by mechanical and dynamic mechanical means indicates the main chain degradation of silicone, some stiffening of EPDM rubber, a change in morphology during weathering and a considerable protection to the blend by EPDM during hydrothermal weathering. An oxidative crosslinking reaction in silicone vulcanisate is also supported by the kinetic parameters evaluated from the real-time storage modulus measurement during ageing in air. Encouraged by the initial results, detailed measurements and a quantitative approach to fit such measurements have been undertaken. The results are being briefly reported here.