High-performance epoxy composites reinforced with three-dimensional Al₂O₃ ceramic framework

High-performance epoxy composites are prepared by a vacuum infiltration method using a functionalized 3D-Al₂O₃ skeleton as the reinforcement and conducting framework. The preformed, porous thermal conducting framework acts as a highway for phonon transfer and can resist a high external loading to protect the epoxy composites. Consequently, a remarkable thermal conductivity of 4.356 W·m⁻¹·K⁻¹ is achieved for the 3D-43 vol%Al₂O₃/epoxy composite, which is 2.7 times higher than that achieved for epoxy composites with conventional randomly dispersed 40 vol% Al₂O₃ particles. The thermal conductivity of the composites with lower interface resistance was higher than that of 3D-43 vol% Al₂O₃/epoxy composite with non-functionalization (3.796 W·m⁻¹·K⁻¹), because of the enhanced Al₂O₃/epoxy interface adhesion. Moreover, the 3D skeleton provides a dual advantage in its prominent reinforcement and toughening of the epoxy composites. The inclusion of 80 vol% of Al₂O₃ preform dramatically enhanced the flexural strength (352 MPa) by 318%, compared to that of neat epoxy.