Simultaneously improving flame retardancy and dynamic mechanical properties of epoxy resin nanocomposites through layered copper phenylphosphate

To improve the flame retardancy of epoxy resin (EP), copper phenylphosphate (CuPP) nanoplates were designed and prepared by mixed solvothermal technique, which were incorporated into EP matrix and fabricated EP/CuPP nanocomposites. The results showed that the product was Cu(HO3PC6H5)2 with appropriate thermal stability, and EP/CuPP nanocomposites displayed excellent catalytic charring performance compared with pure EP. The combustion results indicated that pure EP had no rating and its LOI value was only 23.0%. With incorporation of 4 wt% CuPP, EP/4 wt% CuPP nanocomposites passed the UL-94 V1 rating and the LOI value reached 38.2%. The improved flame retardancy of EP/CuPP nanocomposites was proved by cone calorimeter test, and the peak heat release rate, total smoke production, peak CO production value of EP/4 wt% CuPP nanocomposites dramatically decreased by 51.7%, 52.4% and 47.3%, which were attributed to the formation of hard and condensed residues layers on the surface of EP nanocomposites. Additionally, the incorporation of CuPP improved the dynamic mechanical performance of EP nanocomposites, which may be due to the reinforcement effect of CuPP with rigid structure.