Electrical conductivity of epoxy composites with silicon carbide powder filler

Specific electrical conductivity of ED-20 epoxy-diane resin with silicon carbide powder filler of different dispersions was investigated. The obtained increase in the specific electrical conductivity of the epoxy resin with the increasing content of the silicon carbide powder filler is explained by the higher value of its particular electrical conductivity than that of the epoxy matrix. It was established that the specific electrical conductivity of investigated epoxy composites also depends on the size of the filler grains and their shape. Samples of epoxy composites and silicon carbide powder with the grains size of 60 to 150 microns have the highest specific electrical conductivity. From the analysis of the theoretical calculations carried out within the model of spherical conductive inclusions and the obtained photographs of the shape of the grains of silicon carbide powder, it follows that such grains have a form close to spherical. An increase of the degree of deviation from the sphericity of the shape of the grains with dimensions d > 150 mu m is the reason decreasing the specific electrical conductivity of both the silicon carbide powder and the obtained epoxy composite samples. The obtained results will have practical applications for the development based on the epoxy-diane resin with silicon carbide powder filler of theconductive antistatic coatings, protective screens against the aggressive action of electromagnetic radiation and radiation, and elements of electronic equipment .