Effect of POSS on the Dielectric Properties of Thermally Aged Epoxy Resin Insulating Materials

Polyhedral oligomeric silsesquioxane (POSS) can significantly improve the short-term insulation ability of epoxy materials under high electric field, which makes epoxy/POSS composites show a wide application prospect in high-voltage power equipment. The changes in performance due to aging is the concern of the long-term application of epoxy materials in power equipment. Therefore, the influence of Glycidyl POSS on the insulation performance of epoxy materials in the aging process needs to be investigated. In this article, different mass fractions of epoxy/POSS composites were prepared and the effect of POSS on the dielectric loss of epoxy materials after thermal aging was investigated. The results show that the addition of a small amount of POSS can effectively inhibit the low-frequency dielectric loss of epoxy insulating materials during thermal aging. Combined with the dc volume resistivity test of epoxy composites and the quantum chemical calculation results of POSS molecules, a possible mechanism of POSS inhibiting the dielectric loss of epoxy resin during thermal aging was proposed. The present work provides a reference for further development of POSS in the field of electrical insulation and the application of POSS modified composites in power equipment such as low-frequency transmission and dc transmission equipment.