Influence of a polymer matrix on the electrical properties of polymer composites based on varistor ceramics

Abstract

Polymer composites with semiconductive filler based on nonlinear zinc oxide ceramics were obtained. Polyethylene or polypropylene was used as a polymer. It was shown that the volt-ampere characteristics of the composites were nonlinear. It was found that for both composite compositions an increase in the filler volume fraction led to an increase in electrical conductivity due to an increase in the number of channels for electric current flow. The temperature dependences of the electrical conductivity of composites were studied in the temperature range 20 – 70 °C. It was shown that for a composite in a warehouse that included polyethylene the temperature coefficient of resistance was positive. But for a composite with polypropylene, the temperature coefficient of resistance was negative.