Core-shell structured ZnO nanorods enable flame-retardant, smoke suppressed and mechanically reinforced epoxy resin composites

The engagement of bio-based materials in the manufacture of flame-retardant has gained particular popularity in the past few years due to the raising environmental concerns. In this paper, a multifunctional nanoparticle ([email protected]) that can confer flame-retardancy, mechanical enhancement and smoke suppression to epoxy resin (EP) is designed by constructing a shell layer containing bio-based materials (tannic acid) on the surface of zinc oxide (ZnO) nanorods. It is found that 10 wt% of [email protected] can impart good flame-retardancy (UL-94 V-0 grade, LOI = 31% and 26.1% reduction in total smoke production (TSP)) and good mechanical properties (Young's modulus increased by 22.86%, hardness increased by 50.0% and storage modulus increased by 92.29%) to the modified EP. These desirable properties come from the multiple synergistic effects between ZnO and TPB. This research offered a viable tactic for the manufacture of EP with a low fire hazard.