Electrical Conduction Mechanism in Carbon Filled Polymers

Carbon filled polymers find wide use in industry. In many instances the carbon is added to impart certain electrical properties to the finished product. This paper addresses itself to the latter application. Carbon filled thermoplastics or elastomers are used in the cable and wire industry mainly to take advantage of their pseudo semi-conducting nature. They are usually extruded as shields on electric power cables. Although these materials are widely used, less is known about the mechanism of charge transport through them than is known on either the pure polymer or the carbon filler itself. In the following paragraphs an attempt will be made to explain the experimentally observed conduction in terms of a combination of two classical conduction mechanisms.