Improvement of the mechanical properties of carbon black-filled ethylene propylene diene monomer using a metallic acrylate salt as filler

Abstract

The effects of aluminum triacrylate on vulcanization, mechanical and morphological properties of filled peroxide-cured ethylene-propylene-diene rubber reinforced with carbon black are investigated. Curing kinetics is studied by rheometer and the results indicate that the curing characteristics are influenced by combination of conventional filler (carbon black) and reactive filler (aluminum triacrylate), because the former one enhances the physical cross-linking and the latter one introduces the ionic cross-linking. The results obtained show that the tensile strength, modulus, hardness and cross-link density were tremendously increased with increase of aluminum triacrylate loading in carbon black–filled ethylene propylene diene monomer. Moreover, the observation on the compounds showed that introduction of aluminum triacrylate reduces the elongation at break, resilience and abrasion of carbon black–filled ethylene propylene diene monomer. Morphology of the fractured surfaces of ethylene propylene diene monomer/carbon black/aluminum triacrylate composites was studied by scanning electron microscope. The morphological study indicates that interaction between the fillers and ethylene propylene diene monomer matrix has been improved by substitution of aluminum triacrylate filler with carbon black. Thus, the formation of ionic cross-links structures from both homo-polymerization aluminum triacrylate and graft co-polymerization of it onto the ethylene propylene diene monomer were the main reasons for the significant improvement in mechanical properties of ethylene propylene diene monomer/carbon black composites.