Preparation and Properties Study of Thermally Conductive Epoxy/Modified Boron Nitride/Graphene Nanosheets Composites

A series of thermally conductive and electric-insulating epoxy composites filled with boron nitride (BN) modified by octadecyl trimethyl ammonium bromide and graphene nanosheets (GNP) were prepared. The effects of modified-BN (BNOTAB) and GNP content on thermal conductivity, electric-insulating and thermal stability properties of epoxy composite were investigated. The results indicate that the BNOTAB can homogeneously disperse into epoxy system. When the mass ratio of BNOTAB/GNP is 6:4 (total filler content is 10%), the thermal conductivity of the composites reached 0.48 W/(m·K), which is 108.7% higher than that of the neat epoxy. Meanwhile, the composite retains excellent electric-insulating property. TGA and DSC results showed that the addition of BNOTAB/GNP filler particles can improve the thermal stability of epoxy resin composites. (paper)