Dielectric properties and corona resistance of Si-B/epoxy nano-composites

In order to meet the increasing requirements for materials in the electrical and electronic industry, in this paper, Si-B oxides were designed and synthesized via the organic monomers of Si and B, and the Si-B/epoxy nanocomposites were prepared by ultrasonic dispersion and thermal curing. The Si-B oxides were dispersed uniformly in epoxy resin with great compatibility and the average size of the particles was about 6 nm. Results showed that with the increase of doping content, the dielectric constant and dielectric loss of the Si-B/epoxy nanocomposites decreased, but the effect on the conductivity was not obvious. The dielectric strength and corona resistance life of the Si-B/epoxy nanocomposites increased at first and then decreased. When the doping content was 6 wt%, the corona resistance life of the Si-B/epoxy nanocomposites reached up to 17.6 h, which was 8.38 times of that of pure EP. It was proved that the dielectric properties and corona resistance of epoxy could be effectively improved by doping the Si-B oxides.