Macromolecular Voltage Stabilizer for Enhanced Initiation Characteristics of Electrical Tree in Silicone Rubber

Improving the electrical resistance of insulating materials is critical for the development of extruded power cables. Incorporating voltage stabilizers into polymeric materials is an effective way to inhibit electrical aging of power cables. However, small-molecular voltage stabilizers usually suffer from poor compatibility with polymers. Herein, we rationally designed and synthesized a macromolecular voltage stabilizer (anthracene grafted polydimethylsiloxanes, An@PDMS) featuring well-dispersed An groups covalently bonded to the curing agent of silicone rubber (SIR). The effects of An@PDMS loading on the electrical performance were investigated. Notably, a significant enhancement (up to 57%) of the initiation voltage of electrical tree was achieved in an optimized An@PDMS/SIR with 1.0 wt% An loading, along with improved ac breakdown strength (BDS), lower dc conductivity, less positive charge accumulation, and concomitant smaller field distortion at room temperature. The highly dispersed and covalently bonded An stabilizer provides sufficient trapping sites for high-energy holes, rendering better insulation performance. Our macromolecular design strategy for voltage stabilizers is attractive for future tailorable engineering polymers.