Thermal conductivity and morphology of non-covalent functionalized graphene/epoxy nanocomposites

High thermal conductive graphene reinforced epoxy composites were prepared. The dispersion and interface between epoxy and graphene are improved by Pyrene-end poly(glycidyl methacrylate) (Py-PGMA). Py-PGMA was synthesized by atomic transfer radical polymerization (ATRP) which was absorbed onto graphene by the non-covalent surface functionalization. Additionally, the Py-PGMA content on graphene is 26 wt% by thermogravimetric analysis (TGA). The functionalized graphene provides the reactivity with epoxy forming chemical linkage, which improved the interfacial interaction, result in enhanced thermal conductivity of epoxy composites. The thermal conductivity of 3phr functionalized graphene based epoxy composite is 0.51 W/mK, which is significantly higher than that of neat epoxy (0.18 W/mK) and 3phr multi-walled carbon nanotubes (MWCNTs)/epoxy (0.36 W/mK). The 2D structure of graphene provides more thermal transfer pathway and lower thermal resistance than that of ID MWCNTs. Thermal conductivity of graphene/epoxy and MWCNTs/epoxy were compared in this study.