Effect of Particle Size on the Mechanical and Electrical Properties of Epoxy/Spherical Silica Composites

The effects of particle size on the mechanical and electrical properties of epoxy/spherical silica composites were studied. The silica particle sizes were varied from 5 to 30 mu m and the filler content was fixed to 60 wt%. Tensile and flexural tests were carried out and the interfacial morphology was observed by scanning electron microscopy (SEM). The electrical insulation breakdown strength was estimated using sphere-sphere electrodes with different insulation thicknesses of 1, 2 and 3 mm. The tensile strength and flexural strength increased with decreasing particle size, while electrical insulation breakdown strength increased with increasing particle size.