Thermally conductive polystyrene/epoxy nanocomposites fabricated by selective localization of hybrid fillers

The effective thermal conductivity of polystyrene (PS)/epoxy (EP) composites filled with aluminum nitride (AlN) nanoparticles and multi-wall carbon nanotubes (MWCNTs) was investigated. The surface of aluminum nitride and MWCNTs were modified in order to fit the nonpolar property of polystyrene and the polar one for epoxy, respectively. A double synergistic effect of enhancement on effective thermal conductivity of the composite was observed, which was profited from the selective localization of hybrid fillers and the formation of three-dimensional thermal transfer pathways. The maximum effective thermal conductivity achieved was 6.09 W/m center dot K with double-phase matrix, which is about 29 times of the pure epoxy and 50 % higher than the composite with single epoxy matrix at the same filler loading. Moreover, it was found that the composite with double synergistic effect is more easily to form 3D heat conductive path under low filler loading, which could be promising for the improvement of processability and facilitating considerable reduction of the cost.