Influence of Beta-Cyclodextrin Functionalized Tin Phenylphosphonate on the Thermal Stability and Flame Retardancy of Epoxy Composites

To enhance the thermal stability and flame retardancy of epoxy resin (EP), beta-cyclodextrin (beta-CD) is successfully introduced into the layered tin phenylphosphonate (SnPP), which is incorporated into EP matrix for preparing EP/beta-CD@SnPP composites. The results indicate that the addition of beta-CD@SnPP obviously improve the thermal stability and residual yield of EP composites at higher temperature. When the amount of beta-CD@SnPP is only 4 wt%, EP/4 beta-CD@SnPP composites pass V-1 rating, and LOI value is up to 30.8%. Meanwhile, beta-CD@SnPP effectively suppress the heat release and reduce the smoke production of EP/beta-CD@SnPP composites in combustion, and the peak heat release rate (PHRR), total heat release (THR), smoke production rate (SPR) of EP/6 beta-CD@SnPP composites reduce by 28.4%, 33.0% and 44.8% by comparison with those of pure EP. The good flame retardancy and smoke suppression are ascribed to the synergistic effect of excellent carbon-forming capability and fire retardancy of beta-CD@SnPP.