Abstract
Temperature dependence of resistivity ρ of carbon black(CB)-polyethylene composites below and above percolation threshold pc is studied based on the electrical conduction mechanism. The temperature dependence of ρ of the composites below pc can be explained with a tunneling conduction model by incorporating the effect of thermal expansion of the composite into a tunneling gap. By assuming that the electrical conduction through percolating paths is a thermally activated process and incorporating the effect of thermal expansion into volume fraction p of CB, the temperature dependence of ρ above pc has been well explained without violating the universal law of conductivity and the apparent activation energy is estimated to be 0.14 eV.
