High-performance and multifunctional epoxy composites filled with epoxide-functionalized graphene

Uniform dispersion and strong interfacial adhesion are two critical prerequisites for application of graphene in the polymer composites. To equip the composites with multifunctional character, as little damage as possible to, intrinsic structure of pristine graphene (pG) is also normally required. With these ends in view, an epoxide-functionalized graphene (G-EP) was designed, synthesized, and applied for developing the high-performance and multifunctional epoxy composites. Since the structure and properties of pG are largely inherited and the introduced epoxide moieties ensure the good dispersion and covalent connection to epoxy network, G-EP exhibits an outstanding filler efficiency compared with pG and other graphenic fillers previously explored in epoxy matrix. The resultant composite with only 1.0 wt% G-EP acquires 116% and 96% increments in tensile strength and Young's modulus, respectively, relative to neat epoxy. Furthermore, the electrical percolation threshold is down to 0.16 vol% (0.33 wt%) G-EP, and the thermal conductivity (TC) reaches up to 3.138 W/(m K) at 10 wt.% G-EP that corresponds to a TC increment of 189% per 1.0 wt% G-EP loading or 370% per 1.0 vol% loading. A new type of high-performance, multifunctional but much lightweight epoxy composites is thus in prospect. (C) 2016 Elsevier Ltd. All rights reserved.