The mechanism of electrical conduction in polyethylene/carbon black composite

The mechanism of electrical conduction in the polyethylene (PE)/carbon black (CB) composite is investigated. It is found experimentally that there are three distinct regions in the J-E curve of the PE/CB composite. On the basis of the energy bands of the conductance grain-insulation dielectric-conductance grain system, the electrical conduction equation can be derived correspondingly according to the change in barrier potential under different electric fields. It shows that J∝E at low field strength, Log J/E∝E at middle-field strength and Log J/E∝-1/E at high field strength. The equations fit well with the results obtained from experiments. The evidence suggests that the conduction mechanism in the PE/CB composite can be attributed to electrons tunnelling through the intergranular gaps among the CB particles