No abstract

Ultrathin nickel phenylphosphate (NiPP) nanosheets with layered structure are successfully synthesized through a mixed solvothermal method. The results indicate that NiPP is Ni(O3PC6H5)·H2O and has good thermal stability. To ameliorate the thermal stability and flame ratardancy of epoxy resin (EP), EP/NiPP nanocomposites are prepared by incorporating NiPP into EP matrix. The results show that adding NiPP can availably enhance thermal stability at high temperature due to the remarkable catalytic char performance of NiPP, and the residues yield of EP/NiPP nanocomposites with 6 wt% NiPP is 24.1% while the pure EP had only 14.2% at 700°C. In contrast with pure EP, the peak heat release rate, total heat release, smoke production rate, CO production, and CO2 production of EP/6wt%NiPP nanocomposites reduced by 35.2%, 20.2%, 27.1%, 45.8%, and 35.5%. The synergistic effect of catalytic char performance and fire retardancy of NiPP make the EP/NiPP nanocomposites possess prominent flame retardancy, smoke suppression, and thermal stability.

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-NiCoPO 3) 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 NiCoPO 3 , 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.