Ultrathin iron phenyl phosphonate nanosheets with appropriate thermal stability for improving fire safety in epoxy

Abstract Novel ultrathin iron phenyl phosphonate (FePP) nanosheets has been devised and synthesized with appropriate thermal stability for epoxy resin (EP), which was incorporated into EP matrix for preparing uniformly dispersed EP/FePP nanocomposites with intercalated structure. The results indicate that the incorporation of FePP nanosheets greatly improve the thermal stability and residual yield at higher temperature. When the amount of FePP is only 4 wt%, EP/4 wt%FePP nanocomposites is close to V-0 rating with 15 s of t1+t2 value, and LOI value is up to 35.1. Meanwhile, FePP nanosheets availably inhibit the heat release and restrict the smoke and toxic gas production of EP/FePP nanocomposites in combustion, and the PHRR, THR, TSP and COP peak values of EP/4 wt%FePP nanocomposites reduce by 42.6%, 26.3%, 33.3% and 49.8% by comparison with those of pure EP. The outstanding flame retardancy and smoke suppression performances were ascribed to ultrathin FePP nanosheets with appropriate thermal stability, outstanding catalytic carbonization performance of iron and excellent synergistic flame-retardant capability of phosphorus compounds.