Recyclable flame-retardant epoxy composites based on disulfide bonds: Flammability and recyclability

A series of recyclable epoxy resin (REP) composites are successfully prepared in this study, aiming to improve flame retardancy while keep good recyclability and mechanical properties. The commercial 9,10-Dihydro-9-oxa-10-phosphaphenanthrene 10-Oxide (DOPO) with high reactive P-H bond is used as highly-efficient retardant work. Compared pure a limited oxygen index 21.7 % no rating vertical burning test, only 3 wt% DOPO acquires value 27.8% V-0 rating. In addition, REP containing 4 displays quick self-extinguishing behavior, which shows the 43.5% drop peak heat release rate. main reason might be that traditional phosphorous-containing existing can play positive role both condensed phase gas when burning. On other hand, scanning electron microscopy Raman results also further affirm improved retardancy. Moreover, flame-retardant maintain transparency As well favorable originated from special exchangeable disulfide crosslinks. High-Performance possessing expected retardancy, properties pave way broaden applications thermoset materials.