Effect of Graphene Oxide-Modified Cobalt Nickel Phosphate on Flame Retardancy of Epoxy Resin

Synergistic effect is an effective strategy for improving the flame retardancy of epoxy resin (EP). In this work, a novel graphene oxide-cobalt nickel phosphate (GO-NiCoPO3) is successfully synthesized, which is incorporated into an EP matrix for preparing EP/GO-NiCoPO(3)nanocomposites. The results show that the limiting oxygen index value of EP/4GO-NiCoPO(3)nanocomposites is as high as 30.3%, and UL-94 can reach V-1 rating. The results of micro-combustion calorimetry indicate that the total heat release value and peak of heat release rate of EP/8GO-NiCoPO(3)nanocomposites are decreased by 41.9 and 23.8% compared with those of pure EP. This is mainly due to the synergistic barrier effect of GO and NiCoPO3, which together have their own advantages. Meanwhile, EP/GO-NiCoPO(3)nanocomposites can form a dense char layer during the burning process and improve the thermal stability of EP/GO-NiCoPO(3)nanocomposites.