The influence of carbon black content on current-voltage characteristics of polymer composites

The influence of the concentration $(C)$ of technical carbon (CB) on the current-voltage characteristics (CVC) of composites based on an ethylene vinyl acetate matrix has been studied. It has been established that in polymer composites with low ($C=5$%) and high ($C\ge25$%) concentrations, the conductivity is practically independent of the electric field strength. In composites with CB concentrations corresponding to the percolation region, the presence of two pronounced segments of the CVC was found. After reaching a certain threshold field, a sharp increase in conductivity was observed. The behavior of the current-voltage characteristics of such composites in the region of high fields is described with good accuracy by the Fowler–Nordheim expression.