硅橡胶-炭黑导电橡胶的逾渗特性研究

Percolation characteristics of silicone rubber-carbon black conductive rubber

以炭黑为导电相填充硅橡胶制备导电橡胶,并基于Matlab软件建立了相应体系的逾渗模型,对比研究了炭黑含量及粒径对导电橡胶体系粒子逾渗特性和导电性能的影响。结果表明,当炭黑粒径一定时,炭黑含量是影响所制导电橡胶导电性能的重要因素,当炭黑含量达到逾渗阈值,材料电阻急剧减小,炭黑粒径越小,所制材料的逾渗阈值越低。不同炭黑粒径下,导电橡胶体系的分形维数均随着炭黑含量增加而增大,并且炭黑粒径越小,体系分形维数越小,而分形维数较小的体系在逾渗状态前形成导电集团的能力更强。对比实验和数值模拟结果可知,本文构建的逾渗模型能较好地反映硅橡胶-炭黑导电橡胶中导电相的结合特性。

Conductive rubber was prepared by filling silicone rubber with carbon black as the conductive phase,and a percolation model of the corresponding system was established based on Matlab software.The effects of carbon black content and particle size on the particle percolation characteristics and electrical conductivity of the conductive rubber system were investigated comparatively.The results show that when the particle size of carbon black is certain,the carbon black content is an important factor that affects the electrical conductivity of the as-prepared conductive rubber.When the carbon black content reaches the percolation threshold,the electric resistance of the material decreases sharply;the smaller the particle size of carbon black,the lower the percolation threshold of the as-prepared material.Moreover,the fractal dimension of the as-prepared material increases with the increase of carbon black content at different particle sizes,and the smaller the carbon black particle size,the smaller the fractal dimension of the system.The system with smaller fractal dimension has a stronger ability to form a conductive group before reaching the percolation state.It can be seen from the comparison of experimental and numerical simulation results that the established percolation model can accurately characterize the binding effects of the conductive phase in silicone rubber-carbon black conductive rubber.