新型可回收氮化硼/环氧树脂复合材料导热与介电性能研究

Thermal conductivity and dielectric properties of new recyclable boron nitride/epoxy resin composites

热固性环氧树脂因具有优异的导热性能与绝缘性能在电工装备领域得到广泛应用,由于其具有稳定的三维网络结构和不溶性,回收再利用存在挑战性。本文将不同质量分数的氮化硼(BN)加入到环氧(EP)/4-甲基六氢苯酐降解体系中,制备出高导热、高绝缘、可降解型BN/EP复合材料,并对BN/EP复合材料的导热性能、介电性能以及可降解性能进行研究。结果表明:以2,4,6-三(二甲氨基甲基)苯酚作为催化剂,在乙二醇作用下该BN/EP复合材料可在200℃下实现常压降解。BN质量分数为15%的BN/EP复合材料热导率为0.335 W/(m·K),比纯EP树脂提高了34%;交流电气强度为101.7 kV/mm,比纯EP树脂提高了13%。BN/EP复合材料可经酯交换降解得到EP降解产物(EDP),与EDP复合后,BN/EP复合材料的导热性能和电气强度基本保持不变。

Thermosetting epoxy resin is widely used in electrical equipment field due to its excellent thermal conductivity and insulating properties.Due to the stable three-dimensional network structure and insolubility of the thermosetting epoxy resin,its recycling and reuse pose challenges.In this paper,we added different mass fractions of boron nitride(BN)into the epoxy(EP)/4-methylhexahydrophthalic anhydride degradation system to prepare high thermal conductivity,high insulating,and degradable BN/EP composites,and studied their thermal conductivity,dielectric properties,and degradability.The results show that taking 2,4,6-tris(dimethylaminomethyl)phenol as the catalyst,the EP/BN composites can achieve atmospheric pressure degradation at 200℃under the action of ethylene glycol.The thermal conductivity of BN/EP composite with 15%mass fraction of BN is 0.335 W/(m·K),which is 34%higher than that of pure EP resin;the AC electric strength is 101.7 kV/mm,which is 13%higher than that of pure EP resin.BN/EP composites can be degraded through transesterification to obtain EP degradation products(EDP).After the BN/EP composites are compounded with EDP,the thermal conductivity and electric strength of the BN/EP composites is basically unchanged.