Effect of Graphene on Graphitization, Electrical and Mechanical Properties of Epoxy Resin Carbon Foam

Epoxy resin (EP CF) carbon foam is a new carbon material with a three-dimensional sponge-like structure. The EP CF has high porosity, high temperature resistance, corrosion resistance, and adjustable electrical/thermal conductivity, which possesses broad application prospects. However, epoxy resin is difficult to graphitize. Therefore, graphene was used as a heterogeneous nucleation modifier to improve the graphitization degree, electrical conductivity and mechanical properties of EP CF. Graphene modified EP CF was prepared by a simple process of foaming, carbonizing, and graphitizing. Graphene as heterogeneous nucleation agent induce the carbon crystallite growth in EP CF, which increases the lattice fringe length and reduces carbon crystal tangled. The results show that the interplanar spacing (d₀₀₂), grain stacking height (L_c) and graphitization degree (g) of 0 and 0.05% (in mass) graphene modified EP CF are 0.343 nm, 3.35 nm and 8.42%, 0.342 nm, 10.22 nm and 23.2%, respectively. In addition, graphene as a nucleation site affects the average cell size of EP CF. With the increase of graphene content, the average cell size of EP CF decreases firstly and then increases. Meanwhile, graphene increases the ordered structure of EP CF and improves its conductivity. When graphene is 0.05% (in mass), the conductivity of EP CF is 53.8 S·m^–1. Compared with pure EP CF (compressive strain of 0.0096%), the compressive strains of 0.01%, 0.02%, 0.05%, and 0.1% (in mass) graphene modified EP CF increases to 0.208%, 0.228%, 0.187%, and 0.1146%, respectively. This study provides new research method for the preparation, carbon structure control, and properties of carbon nanomaterial/carbon foam.