Effect of molding pressure on the electrical conductivity of conductive NBR/PVC composites

Acrylonitrile butadiene rubber (NBR) was mixed with different concentrations (1, 3, 5, and 10 phr) of polyvinyl chloride (PVC) and all mixed with 40 phr of high abrasion furnace (HAF) black. The unvulcanizates obtained were subjected to electrical conductivity measurements at different values of moulding pressures. The moulding pressure was found to have an appreciable effect on the electrical conductivity. It decreases sharply as the sample is suddenly compressed and then increases exponentially with time. The interspacing distance between carbon particles or aggregates was calculated on the basis of a simple model proposed by Fernandez et al. (C) 1997 Elsevier Science Ltd.