Effect of Pre-extension on the Electrical Conductivity of Styrene Butadiene Rubber Loaded with HAF and GPF Carbon Black

Abstract

#The effect of pre-extension on the electrical conductivity of the HAF/SBR and GPF/SBR composites with carbon black concentrations of 50, 75 and 100 phr (part per hundred parts of rubber by weight) have been studied. The mechanisms controlling the electrical conduction in the unextended and pre-extended sample have been found to be hopping, tunneling and ohmic conduction mechanisms, respectively. The X-ray integral intensity of the halo (I) increases with increasing the extension ratio. Moreover, the peak of the integral intensity (I) is grown and shifted towards larger scattering angles with increasing the extension ratio. These observations indicate that the polymeric chain segments under extension are stretched and oriented in the direction of extension and more packed side by side. A decrease in the X-ray intensity at high carbon concentrations is thought to be due to a decrease in the dispersion of carbon black as a result of overlapping process of carbon aggregates to form large agglomerates.