Dielectric breakdown of polyethylene-carbon black composites

During the last three decades extensive and worldwide research progress was made with respect to many aspects of percolation phenomena with the advance of computer technology. The physical properties of composites are well expressed as a function of a power law of the distance from the percolation threshold to a volume fraction of a filler with each critical exponent. Electrical properties at high electric fields of composites have not yet been investigated based on the percolation theory in depth. Works on numerical modeling of dielectric breakdown have been done for a random resistor-capacitor network. The aim of this paper is to discuss the dielectric breakdown of carbon black-polyethylene composites based on the percolation phenomena of the composites. The more the dielectric breakdown strength decreases as the more carbon black is loaded. It has been found for the first time that the dielectric breakdown strength of the composites is described by a function of a power law of the distance from the volume fraction of carbon black to the percolation threshold with the critical exponent of /spl nu/ = 0.9.