Electron-beam-modified surface-coated clay: influence on mechanical, dynamic mechanical and rheological properties of ethylene-octene copolymer

Clay filler was surface modified by coating with an acrylate monomer, trimethylolpropane triacrylate (TMPTA) or a silane coupling agent, triethoxyvinyl silane, (TEVS) followed by electron beam irradiation. Both the untreated and the modified fillers, developed by this new technique, were incorporated in an ethylene-octene copolymer. Mechanical, dynamic mechanical and rheological properties of the peroxide as well as electron beam cured unfilled and filled composites were studied in detail. A noticeable improvement in the properties like tensile strength, elongation at break, modulus, tear strength, etc. was observed in the case of surface treated clay-filled rubber vulcanizates. This is more prominent in the silanized clay-filled composite, elucidating strong polymer-filler interaction by the introduction of covalent bonds between the filler surface and the rubber chains. The results obtained from dynamic mechanical thermal analysis further corroborated the above findings. However, the incorporation of the clay filler had marginal influence on the flow properties of the rubber. (C) 2002 Elsevier Science Ltd. All rights reserved.