▎ 摘　　要

Uniform dispersion of graphene nanosheets (GNS) in a polymer matrix with strong filler-matrix interfacial interaction, preserving intrinsic material properties of GNS, is the critical factor for application of GNS in polymer composites. In this work, a novel reactive copolymer VCz-GMA containing carbazole and epoxide group was designed, synthesized and employed to noncovalently functionalize GNS for preparing epoxy nanocomposites with enhanced mechanical properties. The presence of carbazole groups in VCz-GMA enables the tight absorption of copolymer on to graphene surface via - stacking interaction, as evidenced by Raman and fluorescence spectroscopy, whereas the epoxide segments chemically reacts with the epoxy matrix, improving the compatibility and interaction of graphene with epoxy matrix. As a result, the VCz-GMA-GNS/epoxy composite showed a remarkable enhancement in both mechanical and thermal property than either the pure epoxy or the graphene/epoxy composites. The incorporation of 0.35 wt % VCz-GMA-GNS yields a tensile strength of 55.72 MPa and elongation at break of 3.45, which are 42 and 191% higher than the value of pure epoxy, respectively. Increased glass transition temperature and thermal stability of the epoxy composites were also observed. In addition, a significant enhancement in thermal conductivity was achieved with only 1 wt % VCz-GMA-GNS loading. (c) 2015 Wiley Periodicals, Inc.