Thermal Properties of Composites Filled with Different Fillers

Electrical insulating polymers usually incorporate inorganic fillers to achieve specific electrical, mechanical, thermal properties and reduce cost. In this exploratory work, we have studied the thermal properties, at 40degC, of epoxy resin composites with different filler such as: boron nitride, alumina, diamond, silicon carbide, and silicon nitride, with particle size ranges from micro to nano. The results show that BN is the best material in enhancing the thermal conductivity of the epoxy composites despite the various fillers having comparable or higher thermal conductivities than BN. Our current model shows that large disparities in mechanical modulus - a metric for interfacial compatibility - can cause thermal contact resistance due to increased phonon scattering resulting from the large mismatch between filler particle and resin matrix.