Constructing Porous Alumina Frameworks by Sintering for Enhanced Thermal Conductivity of Polymer Composites

Constructing continuous filler networks in a polymer matrix can significantly improve the thermal conductivity of the composite. In this study, we fabricated porous Al₂O₃ frameworks (f-AO) by decomposing the sacrificial material and sintering to serve as heat conduction pathways in the matrix. Then, epoxy/Al₂O₃ frameworks (EP/f-AO) composites with excellent thermal conductivity were obtained by vacuum infiltration. The pre-constructed Al₂O₃ frameworks and sintering reduce interfacial thermal resistance by 1 order of magnitude and result in a dramatically enhanced thermal conductivity of EP/f-AO composites. At the filler content of 49.5 vol %, the thermal conductivity of the EP/f-AO composite is 6.96 W m^-1 K^-1, which is 4.3 times that of the EP/AO composite (1.61 W m^-1 K^-1) with randomly dispersed fillers. The heat dissipation capability of the EP/f-AO composites was further confirmed by infrared thermal imaging. This study provides a promising approach for fabricating thermal conductive polymer composites as electronic package materials.