Effect of coupling agent on PD resistivity of unsaturated polyester - alumina nano-composites

Partial discharges occur in medium and high voltage insulation systems which result in the degradation of the system and lowers performance life. Research on methods to lower partial discharges or contain harmful effects of this phenomenon is of utmost importance. The use of coupling agents has shown to increase the performance of composite systems with respect to the erosion resistance in the case of epoxy composites as well as increase overall performance of composites. The present study focuses on a nano-alumina unsaturated polyester composite system with respect to the effect of particle and coupling agent concentration on the erosion resistance, mechanical and thermal properties. It was observed that an optimum nano-alumina concentration was observed below 1.0 parts per hundred resin (phr) and concentration of coupling agent at 100 parts per hundred of nano-particle. It was observed that along with an increase in the erosion resistance of the composites the overall mechanical and thermal properties were seen to increase. The decrease in performance of composites at higher concentrations of coupling agent and particles was caused due to a lowering of crosslink density of the resultant composites.