Qualification of the electrical conductivity of carbon black filled polymeric materials

The basic conducting behavior of semiconducting materials employing various loading amounts of carbon black dispersed in several polyolefin materials was studied. As base polymers, ethylene-vinyl-acetate copolymers, ethylene-ethyl-acrylate copolymers, and low-density polyethylene were used. In the cross-linkable, carbon black loaded conductive materials, the higher molding temperature gave superior conductivity even under equal amounts of carbon black loading. The predominant conducting mechanism may change according to the amount of carbon black; at a lower loading level, ionic conduction may predominate. The polarity of base polymers seems to play an important role with regard to dispersibility of carbon black and conduction energy. Stabilized conduction will be obtainable by the choice of the comonomer content of base polymer, since larger polarity gives a smaller change of conductivity at room temperature and 90°C