Effect of a Novel Graphene on the Flame Retardancy and Thermal Degradation Behavior of Epoxy Resin

Abstract

The effect of graphene modified with a phosphorus and silicon-containing compound (GO-DOPO-V) on the flame retardancy and thermal stability of epoxy resin (EP) was studied by cone calorimetry and thermogravimetric analysis (TGA) in nitrogen. After incorporation of 2 wt% GO-DOPO-V into EP, maximum decreases of 28.8% in peak heat release rate (pHRR) and 15.6% in total heat release (THR) were achieved compared to that of pure EP. It was shown that GO-DOPO-V significantly promoted the formation of an EP tight char layer and the char residue of EP/GO-DOPO-V composite at 600 °C was 13.39 wt%, which was almost twice that of pure EP. Furthermore, the non-isothermal degradation behavior of EP/GO-DOPO-V composites were investigated also in a nitrogen atmosphere. It was found that the addition of GO-DOPO-V changed the degradation behavior of EP composites in the early and middle stages. Both the Kissinger and Flynn–Wall–Ozawa methods revealed that the addition of GO-DOPO-V increased the thermal degradation activation energy of EP, and improved the flame retardancy of the polymer matrix.