Resistive and dielectric properties of carbon black (MA600)-polyethylene composites

The resistivity and dielectric constant and their dependence on frequency and temperature were measured in order to clarify the change of aggregations with carbon loading. It has been suggested that there are conducting paths related to networks and branches related to dielectric constant above the percolation threshold where resistivity shows a PTC. It has been concluded that the behavior of branches for temperature is independent of that of conducting paths and branches are formed with weak aggregations. In high carbon loading, isolated carbon aggregations change into conducting paths and branches with heating and that contributes to a part of the negative temperature coefficient of resistance and the increment of /spl epsiv/r'.