Effective improvement of anti-tracking of addition-cure liquid silicone rubber via charge dissipation of fluorosilane-grafted silica

Chixin Xie, Xuejun Lai, Hongqiang Li, Xingrong Zeng*

Abstract:  Improving the anti-fouling and anti-tracking of silicone rubber (SR) is significant to enlarge its application in the field of outdoor high voltage insulation. In this work, fluorosilane-grafted silica (F–SiO₂) was prepared by the grafting reaction of silica with perfluorooctyltriethoxysilane. Inclined-plane test (IP test), surface potential decay test, plasma irradiation, XPS and SEM were applied to study the effect of F–SiO₂ on the anti-tracking of addition-cure liquid silicone rubber (ALSR). The results demonstrated that F–SiO₂ postponed the occurrence of intensive arc discharge and reduced arc discharge on ALSR surface. The anti-plasma irradiation and anti-tracking of ALSR were remarkably enhanced. When F–SiO₂ content was 1 phr, ALSR/F–SiO₂ passed the 1A4.5 kV IP test and the erosion mass was only 0.22 wt%. Moreover, the mechanical properties and hydrophobicity of ALSR were improved. Surface potential decay test showed that F–SiO₂ could dissipate charges. Combining its excellent anti-plasma irradiation, it was revealed that F–SiO₂ dissipated the injected charges and diminished the density of charges in ALSR during the arc discharge, which reduced the damage of charges to ALSR chains and suppressed the arc discharge. Therefore, the anti-tracking of ALSR was enhanced.

论文链接：http://dx.doi.org/10.1016/j.polymdegradstab.2019.06.014