Research progress on the preparation of boron nitride nanosheets and its reinforcement on the thermal conductivity of epoxy resin composites

With the significantly increasing demand for new thermal interface materials with high thermal conductivity and high insulation, epoxy resin(EP) with various excellent properties has been widely used as the matrix of thermal conducting composites. However, its practical application is limited by its inherent low thermal conductivity. The incorporation of two-dimensional boron nitride nanosheets(BNNS) with high thermal conductivity and high insulation into epoxy resin can effectively overcome the shortcomings of EP and thereby significantly improve the comprehensive performance. Based on the domestic and foreign research progresses, various preparation methods of BNNS are discussed in this article, such as mechanical exfoliation, hydrothermal exfoliation, liquid exfoliation and chemical vapor deposition(CVD), and their advantages and disadvantages are summarized. Various strategies for improving the thermal conductivity of BNNS/EP composites is reviewed, including surface modification of BNNS, hybridization between BNNS and multi-dimensional fillers, and construction of 3D-BNNS thermal conductivity network. The key problems in the preparation of BNNS/EP composites with high thermal conductivity are proposed; Finally, the development trend of BNNS/EP composites is prospected.