Improvement of tracking resistance of silicone rubber via synergistically promoting ceramization with fluorophlogopite and platinum-nitrogen system

Efficient surface ceramization during the arc discharge is proposed as an efficient strategy to improve the tracking resistance of silicone rubber (SR). Herein, a tracking resistant silicone rubber (FPNs/Pt-NS/SR) with efficient ceramization was fabricated by introducing a small amount of fluorophlogopite nanosheets (FPNs), Karstedt's catalyst (Pt) and aminopropyltriethoxysilane (NS) into SR. FPNs/Pt-NS/SR2 containing 0.50 phr FPNs had excellent tracking resistance and passed 1A4.5 level. After heating treatment at 1000 °C, FPNs/Pt-NS/SR2 transformed into a rigid ceramic with a flexural strength of 7.54 MPa. It was revealed that the radical coupling reaction of SR chains was synergistically catalyzed by FPNs and Pt-NS at high temperature, which promoted the organic-to-inorganic conversion of the SR matrix to form rigid SiOC-like ceramic. When subjected to arc bombardment, the FPNs/Pt-NS/SR2 surface ceramized rapidly and formed a compact ceramic barrier, inhibiting the generation and development of tracking, thus efficiently improved the tracking resistance. This work provides a new strategy for preparing high-performance tracking resistant SR, which has wider application in the field of high-voltage insulation.