Improved through-plane thermal conductivity of 3D structured composites via BN alignment and AlN surface modification

Efficient heat-flow pathways must be built in order to improve the thermal management performance of materials. In this respect, an effective approach is the fabrication of three-dimensional (3D) network structures to generate thermally conductive polymer composites. Herein, aluminum nitride/boron nitride/epoxy (AlN/BN/EP) composites with a 3D foam structure (3D-AlN/BN/EP) are fabricated to take advantage of the thermal behavior of ammonium bicarbonate and the curing properties of the epoxy resin. The 3D foam-structured composite with a filler loading of 50 wt.% is shown to provide a 657% enhancement in thermal conductivity compared to that of the pure epoxy resin. It is also superior to randomly distributed composite materials. In addition, silane-treated AlN is shown to provide composites with increased thermal conductivity and mechanical strength. Therefore, the process described herein provides an easy way to significantly reinforce the thermal conductivity of polymer composites.