| Abstract: | It is of great significance and challenge to efficiently improve the tracking and erosion resistance of silicone rubber along with the growing requirements in the field of outdoor high voltage insulation. In this work, we herein proposed an effective way to address this issue by incorporating vinyltriethoxysilane (ViTES) and layered Mg–Al double hydroxide (LDH) into high temperature vulcanized silicone rubber (HTVSR). ViTES/LDH notably enhanced the tracking and erosion resistance of HTVSR. With addition of 3.33 phr ViTES and 5.00 phr LDH, the anti-tracking performance of HTVSR reached the 1A 4.5 level, and the eroded mass was merely 0.3%. The results of scanning electron microscopy and equilibrium swelling showed that ViTES substantially improved the interfacial interaction between HTVSR and LDH and the crosslinking density of HTVSR, and enhanced the dispersion of LDH sheets in the HTVSR matrix. The possible synergistic suppression mechanism of ViTES/LDH on the tracking and erosion of HTVSR was further studied and demonstrated by the plasma irradiation analysis, thermogravimetry and thermogravimetry-Fourier transform infrared spectrometry. It was indicated that under the high voltage arcing discharge, LDH facilitated the formation of a dense barrier layer consisting of bimetal mixed oxides on the HTVSR surface, exerting outstanding lamellar barrier effect. The further degradation and the generation as well as development of electrical tracking were efficiently suppressed. Our findings provided a new approach to fabricate silicone rubber with excellent tracking and erosion resistance. |
