Time–Temperature Dependence of the Electrical Resistivity of High-Density Polyethylene/Carbon Black Composites

ABSTRACT: Several carbon blacks with surface areas from 105 to 1353 m2/g were used to produce composites through melt compounding with a high-density polyeth-ylene matrix. The electrical behavior of the obtained com-posites was investigated by the measurement of their re-sistivity as a function of the carbon black content and type at various temperatures and times during isothermal annealing treatments. The percolation threshold mark-edly decreased as the carbon black surface area increased, reaching a minimum value of 1.8 vol % for the carbon black with a surface area of 1353 m2/g. The resistivity passed through a maximum as the test temperature increased. Moreover, the analysis of the experimental data evidenced that the host high-density polyethylene matrix and the conductive carbon black network rear-ranged during the isothermal thermal treatments, causing a resistivity decrease. This rearrangement became less and less important as the carbon black surface are