Thermal conductivity of epoxy resin composites filled with combustion-synthesized AlN powder

The thermal conductivity of epoxy resin composites filled with combustion-synthesized aluminum nitride (AlN) particles was investigated. The mixing of the composite constituents was carried out by either a dry method (involving no use of solvent) for low filler contents or a solvent method (using acetone as solvent) for higher filler contents. It was found that surface treatment of the AlN particles using a silane, 3-aminopropyltriethoxysilane (APTES), increases the thermal conductivity of the resultant composites by a less amount compared to most of the values reported in other studies. This was explained by that the combustion-synthesized AlN particles contain less-OH or active sites on the surface, thus adsorbing less amounts of APTES. However, the thermal conductivity of the composites filled with the combustion-synthesized AlN was found to be within the range of the values reported in other studies where commercially available AlN was used. Effects of several factors on the thermal conductivity of the epoxy resin composites were investigated including filler content (10-60 vol%), particle size (2.5-22.4 mu m), oxygen content (0.22-2.20 wt%) and with or without surface treatment. Within the ranges of the factors investigated in this study, it was found that the filler content has the greatest effect on the thermal conductivity of the composites. The effects of the other three factors on the thermal conductivity of the composites increase roughly with increasing filler content. Among the three factors, the effect of particle size on the thermal conductivity was found to be greater than that of the other two. POLYM. COMPOS., 39:E2125-E2133, 2018. (c) 2017 Society of Plastics Engineers