A Novel Anderson-Type POMs-Based Hybrids Flame Retardant for Reducing Smoke Release and Toxicity of Epoxy Resins.

Smoke emission and smoke toxicity have drawn more attention in improving the fire safety of polymers. In this work, we prepared a POMs-based hybrids flame retardant (P-AlMo ) epoxy resin (EP) with toxicity-reduction and smoke-suppression properties via a peptide coupling reaction between polyoxometalates (POMs) and organic molecules with double DOPO (bisDOPA). It combined the good compatibility of the organic molecule and the superior catalytic performance of POMs. Compared to pure EP, the glass transition temperature and flexural modulus of EP composite with 5 wt% P-AlMo (EP/P-AlMo -5) were found to be raised by 12.3°C and 57.75%, respectively. Notably, at low flame-retardant addition, the average CO to CO ratio (Av-COY/Av-CO Y) was reduced by 33.75%. Total heat release (THR) and total smoke production (TSP) were lowered by 44.4% and 53.7%, respectively. The Limited Oxygen Index (LOI) value achieved 31.7% and obtained UL-94 V-0 rating. SEM, Raman, XPS, and TG-FTIR were applied to analyze the flame-retardant mechanism in condensed phase and gas phase. Outstanding flame retardant, toxicity-reduction, and smoke-suppression properties were attained due to the catalytic carbonization ability of metal oxides Al O and MoO produced from the breakdown of POMs. This work advances the development of POMs-based hybrids flame retardants with toxicity-reduction and smoke-suppression properties. This article is protected by copyright. All rights reserved.