A fractographic study on toughening of epoxy resin using ground tyre rubber

This study is a fractographic examination of epoxy resin modified with scra p car tyre regrinds used as toughening phase. Five different surface treatm ent techniques, used to improve the compatibility at the interface between the rubber particles and the epoxy matrix, were: oxygen plasma, two silane coupling agents, acrylic acid and acrylic acid/benzoylperoxide mixture. Rub ber parts of ground scrap car tyres with a size range of 355-500 mum after surface treatment were mixed with epoxy. This mixture was poured into molds to obtain fracture toughness test specimens. After curing, plane strain fr acture toughness tests were performed and the fractured surfaces of the spe cimens were examined under the scanning electron microscope. Fractographic studies indicated that the increase in fracture toughness values were due t o the improved interface leading to crack deflection as the main rubber tou ghening mechanism. Secondary rubber toughening mechanisms observed were she ar deformation and some debonding initiated at the interface. (C) 2001 Else vier Science Ltd. All rights reserved.