Dielectric breakdown performance of alumina/epoxy resin nanocomposites under high voltage application

Abstract Epoxy/alumina nanocomposites were prepared by reducing micron size alumina into nanosize during the casting process. In our current investigation it was found that, at low concentration alumina nanoparticles exhibit uniform dispersion of alumina nanoparticles in epoxy nanocomposite while at higher concentration they depict aggregation of alumina particle. Since uniform dispersion of alumina nanoparticles results in improved thermal stability and viscoelastic behavior. It leads to remarkable improvement in breakdown voltage, and breakdown time of epoxy/alumina nanocomposites as compared to neat epoxy. Epoxy nanocomposites containing 2 wt.% of alumina particles results in increase of breakdown voltage by 91% and breakdown time by 155% as compared to neat epoxy. Hence, the nanocomposites developed can be used as insulating material in electrical instruments which require high breakdown voltage as well as improved viscoelastic behavior and thermal stability.