Enhancement of thermal conductivity of BN/epoxy composite through surface modification with silane coupling agents

Abstract The thermal conductivity of boron nitride/epoxy composite was increased by up to 45.4% through surface modification of BN. The silane coupling agents with different main carbon chain (C3 and C16) were introduced on the BN surface through sol-gel reaction to improve the affinity of BN with epoxy resin. The surface-modified BN exhibits the higher dispersibility in epoxy than as-prepared BN. In the case of the modified BN samples, the dispersion was more stable as increasing the length of carbon main chain of silane. It means that the higher interfacial adhesion of BN/epoxy composite could be obtained by introducing the longer carbon chain on BN surface. Using the surface modification, the thermal conductivity of the treated BN with HDTMS reached to 3.49 W/m K through decrease of the thermal contact resistance at the BN/epoxy interface. As a result, the enhancement of thermal conductivity could be controlled by varying the surface property of BN.