New approach to elucidate the properties of carbon black-filled semiconducting materials for high voltage power cables

The authors have studied the basic electrical behavior of semiconducting materials employing a variety of CB (carbon black) loading amounts dispersed in several polyolefins. In the present work, the electrical conductivity of CB filled semiconducting materials is shown to depend on the nature of the CB network in the polymer matrix. The growth of the network may be accelerated by thermal vibration since higher molding temperature gives stable and enhanced conductivity. Both the amount of bound polymer and the dielectric breakdown strength seemed to predict the level of CB network development. Transmission electron microscope (TEM) observation of these semicon materials gave direct evidence for a well-grown CB network with high electrical conductivity