Effect of organophilic group of coupling agent on the electrical performance of Boron Nitride/meta‐aramid composite paper

Abstract

Abstract Organophilic groups of coupling agents can be the key factor for the electrical performance of Boron Nitride (BN)/meta‐aramid composite paper. In this article, four types of triethoxy‐silane coupling agents with different organophilic groups, including mercapto‐propyl (MP), glycidylether‐propyl (GP), amino‐propyl (AP) and trideca‐fluoro‐octyl (TFO) were studied. The structural and electrical properties of modified papers were compared, and the molecular simulation was conducted to reveal the interface interaction of modified BN and aramid. The results show that AP, GP and MP follow the same mechanism, improving the electrical performance by modifying the interface stability and paper structure, and the ranks of improving effects are AP, MP and GP. While, TFO mainly relies on the fluorine components to implement the electrical reinforcement, which compensates for the shortcoming in the paper structure. By choosing TFO and filler content of 15 wt%, the optimal breakdown strength of the paper can be increased to 28.17 kV/mm, 1.8 times that of the paper doped with the hydroxylated BN.