Electrical Conductivities of High-Density Polyethylene Composites Reinforced With Carbon Fiber and Nanometer Carbon Black

The effect of carbon fiber (CF) content on the electric conductive behavior of high-density polyethylene composites filled with 10 wt% nanometer carbon black (CB) was investigated. It was found that the influence of the CF and CB on the resistivity was not the sum of these two fillers; the resistivity varied slightly and irregularly when the CF weight fraction was lower than 6 wt%, and then decreased quickly. The intensity of positive temperature coefficient (PTC) increased first and then decreased with increasing the CF weight fraction; when the CF weight fraction increased to 12 wt% from 8 wt%, the PTC intensity of the composite systems increased to 6.6 from 3.4; when the CF weight fraction increased to 15 wt% from 12 wt%, the PTC intensity of the composites decreased to 4.8 from 6.6. This could be attributed to the aggregation of the conductive filler in the matrix in this case. (C) 2018 Society of Plastics Engineers