Dielectric Properties and Corona Resistance of Si–Mg–B/EP Nano-composites.

In order to meet the increasing requirements of epoxy resin matrix materials for the electrical and electronics industry, this paper presents the design and synthesis of Si–Mg–B oxides using Mg, Si and B organic monomers, and preparation of Si–Mg–B/EP nanocomposites by ultrasonic dispersion and thermal curing. Mainly study the effect of composite oxide introduction on the dielectric properties of epoxy resin composites. With an increase in doping amount, the Si–Mg–B/EP nanocomposites show an increase in dielectric constant under working frequency test conditions; a decrease in dielectric loss followed by an increase, and the lowest value of 0.00238 is obtained at a doping amount of 8 wt%. The volume resistivity initially increases and then decreases, with the maximum value of 5.64 × 1016 Ω cm obtained at a doping amount of 8 wt%. Furthermore, the corona resistance life of Si–Mg–B/EP nanocomposites increases, with a value of 401.8 min obtained at a doping amount of 8 wt%, which is 4.65 times that of pure EP. And the morphology near the breakdown point of corona breakdown was analyzed. These results suggest that Si–Mg–B oxide is effective in improving the dielectric loss and corona resistance of epoxy resin. [ABSTRACT FROM AUTHOR]