Study on liquids diffusion into and relevant corrosion behaviour of glass fibre reinforced polymer used in high voltage composite insulator

Abstract

Long-term liquids diffusion tests were performed on glass fibre reinforced polymer (GFRP) used in high voltage composite insulator. The plate-shaped GFRP specimens were immersed in three types of liquids, which high voltage composite insulator would encounter in practice, including deionised water, NaCl solution and nitric acid solution for a period of 4000 h. Chemical reaction and physical dissolution complicated the diffusion processes, which could be divided into three types based on the features of diffusion curves. Fourier transform infrared spectroscopy, scanning electron microscopy and optical interferometry were employed to investigate the chemical property, two-dimensional (2D) and 3D surface morphologies of GFRP. The results revealed that the surface layer of GFRP was destroyed to some extent depending on the type and concentration of the liquid, the maximum of profile height deviation of GFRP surface was proposed to evaluate the extent of the corrosion of GFRP, the greater the profile height deviation, the more serious the corrosion of GFRP. The present work is helpful for a better understanding of the diffusion behaviour of liquids into GFRP used in high voltage composite insulator as well as in other industry applications.