Three dimensional porous alumina network for polymer composites with enhanced thermal conductivity

In this work, a desirable continuous alumina (Al2O3) framework with honeycomb-like morphology was realized in epoxy/Al2O3 composites through a well-designed protein foaming technique followed with infiltration. High sintering was employed to reduce the interfacial thermal resistance between fillers, as well as improving the mechanical strength of the framework in the meantime. Owing to the well-ordered filler network in epoxy, the interfacial thermal resistance was decreased by one order of magnitude. Besides, the maximum thermal conductivity reached 2.58 W/m·K, 3.6 time higher than that of epoxy/Al2O3 composite with randomly dispersed Al2O3 at the filler loading of 23.32 vol%. In addition, the prefabricated 3D-Al2O3 scaffold also has a great strengthen effect on thermal stability, dimensional stability, and dynamic mechanical property for the composites due to the unique structure. This strategy paves an effective way for developing epoxy composites with good thermal performance in electronic packaging applications.