A Cu‐MOF‐decorated ammonium polyphosphate for epoxy resins with reduced smoke release and enhanced char layer

Abstract Inspired by the significant catalytic charring effect of metal–organic frameworks (MOFs), Cu‐MOF decorated ammonium polyphosphate (APP@Cu‐MOF) was prepared by coupling agents to improve the fire safety of epoxy resin (EP). After adding 9 wt% APP@Cu‐MOF, the fire performance of EP is significantly improved with limiting oxide index (LOI) value of 29.4 and UL‐94 V‐0 rating. The peak heat release rate (PHRR), total smoke production (TSP), CO production, and CO 2 production of EP composite samples decreased by 34.6%, 54.7%, 24.6% and 30.0%, respectively. It is proposed that the synergistic effect among Cu‐MOF and APP promoted the char formation of EP. The dense carbon layers formed a barrier that prevented the transfer of heat and inhibited the release of toxic gases, thus acting as a flame retardant. This work provides a new strategy to develop a high‐efficient MOF‐decorated flame retardant with smoke inhibition, toxicity reduction, and catalytic carbonization effect.