Effect of Silica Particle Size on the Mechanical Properties in an Epoxy/Silica Composite for HV Insulation

In order to develop a high voltage insulation material, epoxy/micro-silica composites (EMC) and epoxy/micro-silica/nano-silica composites (EMNC) with three different particle sizes in μm and one particle size in nm were preparedand their tensile and flexural tests were carried out and the data was estimated by Weibull statistical analysis. Thetensile strength of the neat epoxy was 82.8 MPa and those of the EMCs were larger than that of the neat epoxy, andthey were much more advanced by the addition of 10 nm sized nano-silica to the EMCs. Flexural strength showed thesame tendency of the tensile strength. As the micro-particle size decreased, tensile and flexural strength increased.