Characterization of mechanical properties of irradiated EPDM copolymer composites loaded with carbon black and aluminum tri-hydroxide

Abstract

Ethylene propylene diene rubber (EPDM) is known by its heat resistance and excellent electrical properties besides an effective radiation resistance. EPDM compositions containing carbon black and aluminum tri-hydroxide (ATH) were prepared and further irradiated aiming to evaluate mechanical performance as well the influence of these agents on compounds degradation. There were developed vulcanizable formulations with EPDM elastomer; besides addition of conventional additives for elastomers, inorganic loads, N-330 carbon black and aluminum tri-hydroxide were added too. Composites were subjected to gamma-radiation at 25 kGy , 50 kGy, 100 kGy and 200 kGy doses. Irradiated and non-irradiated composites were assessed as per mechanical-physical properties such as hardness, tensile, elongation at break, among others. It was verified that mixtures containing carbon black showed a better performance of mechanical properties for both non-irradiated and irradiated compositions; it was observed too that for irradiated composites at 200 kGy occurred the predominance of chain-scission.