Abstract: Using phenylphosphonic acid and ferric nitrate as raw materials, ethanol and ethylene glycol as solvents, polyvinylpyrrolidone and hexamethylenetramine as surfactant and coordination agent, the layered compound iron phenylphosphonate (FePP) was prepared by mixed solvent method and then added into epoxy resin (EP). The thermogravimetric (TG) results showed that FePP could improve the thermal stability of EP. At the same time, the UL-94 level of EP/4FePP passed V-1, and the limit oxygen index (LOI) increased accordingly. In order to further improve the flame retardant performance of EP, FePP was mixed with phosphorus containing flame retardant DOPO to flame retardant EP. The test results showed that EP/3DOPO/1FePP nanocomposite can pass UL-94 V-0, and the LOI value was up to 34.5%. The peak heat release rate (PHR) and total heat release rate (THR) decreased by 28.4% and 18.1%, respectively, compared with pure EP. This was mainly because FePP can degrade into oxides containing phosphorus and metal during combustion, which promotes rapid carbonization of polymer. Moreover, DOPO can capture free radicals in gas phase, inhibit the chain reaction, and inhibit combustion. So as to achieve the gas phase and condensation phase co-effect flame retardant effect.

Key words: epoxy resin, iron phenylphosphonate, DOPO, flame retardant, layered compound