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

Abstract

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.