Effects of nanofiller and voltage stabilizer on partial discharge resistance of polypropylene/elastomer blends: A comparison study

Abstract

AbstractThis paper reports on the individual and synergistic influence mechanisms of nano‐silica (SiO2) and voltage stabilizers on partial discharge (PD) resistance of polypropylene blended with ethylene‐octene copolymer elastomer. The SiO2 nanoparticles and three types of voltage stabilizers, that is, benzoin, 4,4′‐dimethoxybenzil, and 3‐aminobenzoic acid are selected as fillers to prepare samples. PD is initiated in a rod‐to‐plane electrode system with an alternating current voltage of 5 kVrms. PD characteristics are captured with multi‐sensors, and the erosion profile of the test sample is measured using a three‐dimensional (3D) optical profilometer. Carrier trap distribution is extracted with isothermal surface potential decay measurement to assist the analysis of PD eroding material. Fourier transform infrared spectrum, scanning electron microscopy, X‐ray diffraction spectrum, and differential scanning calorimetry analysis are performed to reveal the change in material structures caused by the fillers. Test results indicate that the PD resistance of the blend can be improved by the addition of nano‐SiO2 and voltage stabilizers individually and synergistically. The PD resistance of PO is increased by 71.2% at most in the sample with 3 wt% nano‐SiO2 addition. The sample filled with SiO2 exhibits better PD resistance than that with the voltage stabilizer or co‐added, which should be ascribed to the introduction of deep traps, the formation of the packaged layer, the suppression of oxygen diffusion of the nanofillers, and the good compatibility between additives and the polymer matrix.