Effect of filler treatment and crosslinking on mechanical and dynamic mechanical properties and electrical conductivity of carbon black-filled ethylene-vinyl acetate copolymer composites

Mechanical, dynamic mechanical, and electrical conductivity of conductive carbon black-filled ethylene-vinyl acetate (EVA; 28% VA) composites were investigated. The above-mentioned properties were also measured when carbon black was treated with nitric acid before addition to the EVA matrix. It was found that acid-treated carbon black exhibits a higher filler-polymer interaction and this was reflected in the improvement of the mechanical properties and the modification of electrical conductivity of these composites, especially when measured against the temperature. The effect of curing of the polymer matrix on the mechanical properties and electrical conductivity was also investigated. It was found that the introduction of crosslinks in the polymer matrix improves its mechanical properties as well as the thermal stability of its electrical conductivity. The electrical conductivity of ethylene propylene diene (EPDM) and an EVA-EPDM (50/50) blend filled with carbon black were also studied for comparison. (C) 2003 Wiley Periodicals, Inc.