Alumina-graphene hybrid filled epoxy composite: Quantitative validation and enhanced thermal conductivity

Alumina-graphene hybrid fillers (Gr-Al₂O₃) were synthesized and added to the epoxy matrix to improve thermal properties of the epoxy composite. The alumina particles were surface modified with silane coupling agents like 3-Aminopropyl triethoxysilane (A-Al₂O₃). 3-Glycidyloxypropyl trimethoxysilane (GPTMS) was used for the surface modification of the graphene (G-Graphene). These modifications on the filler surface help to develop the interface between the fillers and the epoxy matrix, which might help to form the effective 3D thermal conductive networks. The generation of these 3D networks facilitated in reducing the Kapitza resistance and increases the transportation of phonons in the matrix, Furthermore; it improved the integral procedure decomposition temperature (IPDT) and activation energy (E_a) of the composite. Alumina-graphene hybrid filled epoxy composite (hAG-Epoxy) with 50 vol% of hybrid filler (Gr-Al₂O₃) expressed the considerable improvement in in-plane thermal conductivity and IPDT by ∼8.4 and ∼3.1 folds in comparison with neat epoxy, respectively. The significant improvement in thermal conductivity was related to the generation of effective 3D thermal conductive pathways formed by 2D graphene and 1D alumina in the composite.