Simultaneously improving flame retardancy and dynamic mechanical properties of epoxy resin nanocomposites through synergistic effect of zirconium phenylphosphate and POSS

To simultaneously improve flame retardancy and dynamic mechanical properties of epoxy resin (EP) nanocomposites, layered zirconium phenylphosphate (ZrPP) was successfully synthesized through mixed solvothermal technique and added with polyhedral oligomeric silsesquioxane (POSS) to EP to prepare ZrPP/POSS/EP nanocomposites. The results indicated that molecular formula of ZrPP was Zr(O ₃ PC ₆ H ₅ ) ₂ ·H ₂ O with suitable thermal stability as flame retardant for EP. Based on the synergism of ZrPP and POSS, ZrPP/POSS/EP nanocomposites exhibit higher thermal stability, better flame retardancy, and more residue than pure EP. More importantly, addition of low content of ZrPP optimized dynamic mechanical properties of ZrPP/POSS/EP nanocomposites. Compared with those of 5 mass% POSS/EP, the storage modulus of 1 mass% ZrPP/4 mass% POSS/EP increased by 9% and the glass transition temperature scarcely changed, which was speculated that there were some of three-dimensional POSS molecules intercalating into interlayers of ZrPP and led to excellent dispersion state and increased nanoreinforcing effect in EP nanocomposites.