Novel Si/N/P-Containing Flame Retardant for Epoxy Resin with Excellent Comprehensive Performance

Because of the highly inherent flammability of epoxy resin (EP), its application especially in high-performance fields that have demands on flame retardancy was greatly limited. Herein, a novel Si/N/P-containing flame retardant (PMBZ) was prepared to solve the flammability defects of EP. In particular, the sample with 10.0 wt% PMBZ reached a limiting oxygen index (LOI) of 32.4 % and could successfully pass UL-94 V-0 rating. Meanwhile, there was a 16.1 % and 22.4 % decrease in total smoke production (TSP) and total heat release (THR), respectively. The satisfactory flame retardancy and smoke suppression were due to the introduction of PMBZ, which could function both in condensed and gas phases through forming a compact and coherence self-extinguishing char layer and inducing a dilution effect. More importantly, the tensile strength, impact strength and flexural strength had also increased by 33.0 %, 53.7 % and 20.7 %, respectively, which indicated the incorporation of PMBZ could also maintain its desired mechanical properties due to the excellent compatibility and enhanced intermolecular interactions. This work provides an exploitable flame retardant additive for epoxy resin to guarantee a superior flame retardancy, favorable smoke suppression and mechanical properties.