Surface grafting modification of BN significantly enhanced the thermal conductivity for epoxy resin

Boron nitride, as an excellent thermal conductive filler, has received widespread attention in the field of heat dissipation, and its interface thermal transport with organic matrix is a key issue for improving thermal conductivity. In this study, several typical modifiers are selected to modify boron nitride to improve its interfacial compatibility with epoxy resin. The composition of functional groups, crystal structure and factors affecting thermal conductivity of the modified boron nitride surface are systematically studied. The influence of main factors such as the structural characteristics of grafted molecules and the grafting functional groups on the construction of thermal conductivity channels was analyzed in detail. The results show that shorter chain length and fewer cross-linked branches are more conducive to phonon transport and propagation. The thermal conductivity of BN-KH570/EP composite at 26 wt% load reaches 1.52 W/m center dot K, which is 7.6 times that of pure epoxy resin. It also maintains good thermal stability at 600 degrees C, which provides a new idea for improving the interface interaction of boron nitride composites.