Nanoengineering of brucite@SiO2 for enhanced mechanical properties and flame retardant behaviors

Abstract An efficient halogen-free composite flame retardant (CFR) consisting of a brucite core and a thin SiO 2 shell was synthesized via a facile nanoengineering route. The as-synthesized CFR was employed as a filler material to improve the mechanical performance and flame retardancy of EVA composite. In comparison with that of EVA/brucite and EVA/PM, the mechanical properties of EVA/CFR, especially the tensile strength (TS), presented a remarkable increase reaching at least a 25% increment. Meanwhile, with the same 50 wt% of fillers, the EVA/CFR formulation could achieve a limiting oxygen index (LOI) value of 34 (13% higher than that of EVA/PM blends) and UL-94 V-0 rating. Moreover, the heat release rate (HRR), peak heat release rate (PHRR), total heat released (THR), smoke production rate (SPR) and mass loss rate (MLR) were considerably reduced. Based on the results, the enhanced mechanism for the mechanical properties and flame resistance of CFR particles has been also proposed, which could be mainly ascribed to structural synergy between brucite core and SiO 2 shell. Therefore, the nanoengineering of brucite@SiO 2 might pave the way for the future development of a facile large-scale approach to brucite-based flame retardant materials.