The Low-Temperature Thermal Conductivity of Epoxy Resin Composites Enhanced by Graphene and Modified Alumina Hybrid Fillers

In recent years, polymer/ceramic composites with high thermal conductivity have been widely used in microelectronic devices, superconducting magnets and aviation, and further improving their thermal conductivity is a great challenge. In this work, spherical alumina nanoparticles were modified with 3-aminopropyltriethoxy-silane (APTES) successfully. Furthermore, the modified Al2O3(M-Al2O3)/Epoxy(EP) and Graphene(Gr)/M-Al2O3/EP composites were prepared and their properties were tested in the temperature range of 70 K-300 K. The results showed that the thermal conductivity of the composite with 1 wt% Gr and 60 wt% M-Al2O3 hybrid filler is 15 times higher than that of pure epoxy at 70 K, which indicates its application prospect in thermal interface materials.