PRESSURE-SENSITIVE ELECTRICALLY CONDUCTIVE NITRILE RUBBER COMPOSITES FILLED WITH PARTICULATE CARBON-BLACK AND SHORT CARBON-FIBER

The electrical conductivity of pressure-sensitive nitrile rubber composites, containing different loadings of particulate carbon black filler and short carbon fibre, have been studied. The conductivity of composites increases with increasing of filler concentration as well as with increased applied pressure up to a certain limit. The composites containing particulate fillers register low conductivity as compared to composites containing short carbon fibres, due to easy formation of an interconnecting network in the latter case. The effect of the orientation of short carbon fibre with respect to an applied electric field has also been studied. The pressure dependence of composites with transversely oriented carbon fibres with respect to electric fields is higher than that of composites with longitudinally oriented carbon fibres. The results are interpreted on the basis of the formation of interconnecting continuous conducting networks. © 1990 Chapman and Hall Ltd.