Suppression Effect and Mechanism of Amine-Containing MQ Silicone Resin on the Tracking and Erosion Resistance of Silicone Rubber.

How to effectively enhance the antitracking performance of silicone rubber is a huge challenge in the field of high-voltage insulation. In this contribution, amine-containing MQ silicone resin (A-MQ) was prepared to enhance the tracking and erosion resistance of addition-cure liquid silicone rubber (ALSR). The results showed that A-MQ imparted ALSR with excellent tracking and erosion resistance. When A-MQ content was 4 phr, all test samples passed the inclined plane test at 4.5 kV, and the erosion mass decreased by 67.8%. In addition, the tensile strength and tear strength increased by 13.2 and 13.6%, respectively, compared with that of ALSR without A-MQ. The suppression mechanism was further investigated in the aspects of heat attack and plasma bombardment by laser Raman spectroscopy, thermogravimetry, thermogravimetry-Fourier transform infrared spectrometry, scanning electron microscopy, attenuated total reflection-Fourier transform infrared spectrometry, and X-ray photoelectron spectroscopy. This revealed that at the elevated temperature caused by arc discharge, A-MQ promoted crosslinking of the polysiloxane molecules and suppressed the generation of cyclic oligomers, which reduced the intensity of the electrical arc. Moreover, when suffering from plasma bombardment, which was also produced by arc discharge, A-MQ protected the silicone chains from degradation and eliminated the carbon deposited on the surface.