Chemically modified boron nitride-epoxy terminated dimethylsiloxane composite for improving the thermal conductivity

The thermal conductivities of composites with an epoxy-terminated dimethylsiloxane (ETDS) matrix and boron nitride (BN) powder fillers were investigated. Two surface curing agents, 3-glycidoxypropyltrimethoxysilane (KBM-403) and 3-chloropropyltrimethoxysilane (KBM-703), were doped onto the surfaces of hydroxyl-functionalized boron nitride using a simple sol–gel process to act as fillers in the thermally conducting composites. These synthesized materials were embedded in epoxy resin via a solvent casting method. The surface modification had an appreciable effect on the thermal conductivity resulting in increased thermal conductivity up to 70 wt%. The thermal conductivities of the composites containing 70 wt% BN particles treated with the KBM-403 and KBM-703 curing agents were 4.11 and 3.88 W/mK, respectively, compared to 2.92 W/mK for the composite without surface treatment.