An Aggregate Structure Model of Carbon Black Filled Conductive Composites

The aggregate structure of carbon black is one of the most important influence factors to the percolation threshold of polymer/carbon black conductive composites.In order to reveal this problem,the aggregate structure of carbon black in polymer matrix was analyzed in this paper.An aggregate model of the carbon black particles was proposed based on the effective media theory and the equivalent sphere of carbon black aggregate acts as a basic cell to describe the percolation behavior.A formula describing the relationship between the conductivity and the volume fraction of carbon black particles as well as an expression estimating percolation threshold of the composites were derived.Based on these expressions,the electrical conductivity and percolation threshold of several kinds of conductive composites were predicted and the results showed that the predictions were preferably consistent with the experimental data from the references.