炭黑填充型导电复合材料的聚集体结构模型

分析了炭黑填充聚合物导电复合材料的非线性导电行为和机理,基于有效介质理论及以炭黑聚集体的等效球形单元为基本单元,建立了描述其非线性导电行为的聚集体结构模型。进而推导出复合体系导电率与炭黑体积分数之间的关系式及其逾渗阈值的计算式,克服了有效介质理论只能得到逾渗阈值为1/3而不能解释低于1/3的逾渗阈值的不足。应用这些表达式预测了导电复合体系的导电率和逾渗阈值,并与实验结果进行了比较,结果表明:预测值与实验结果有较好的一致性。

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.