Interfacially-engineered PBA based hierarchical structure with Ni(OH)2 nanocatalyst towards fire retardation of epoxy resin.

• Hierarchical Co@Ni(OH) 2 -A structure is designed via interfacial engineering strategy. • Co@Ni(OH) 2 -A holds strong interfacial catalytic charring and oxidation activities. • Simultaneously enhanced fire safety and mechanical property of polymer are obtained. • Flame retardation contrast with reported works proves the meliority of Co@Ni(OH) 2 -A. The extended usage of epoxy resin (EP) has suffered from the notorious issue of high fire hazard, including the release of considerable heat and emission of abundant toxicants (smoke and toxic gasses). Hence, a prussian blue analogue (PBA) based hierarchical structure (Co@Ni(OH) 2 -A) with Ni(OH) 2 nanocatalyst, is proposed via interfacial-engineering strategy, towards reducing the fire hazard of EP. As revealed, Co@Ni(OH) 2 -A shows strong interfacial catalytic strengths both in charring of decomposed volatiles and oxidizing of toxic gasses. By using 4.0 wt% Co@Ni(OH) 2 -A, the peak heat release rate, peak smoke production rate, total smoke production and peak CO production rate are reduced by 45.5%, 55.0%, 44.3% and 65.3%, respectively. Fire resistance comparison with previous works confirms the advantage of Co@Ni(OH) 2 -A in toxicants elimination. Owing to the well-generated hierarchical structure-polymer interfaces, the greatly enhanced mechanical property is obtained. Generally speaking, Co@Ni(OH) 2 -A holds exceptional efficacy in promoting the polymer fire safety and mechanical performance. This investigation may offer useful enlightenments for acquiring high-performance EP composites via designing PBA based flame retardants with hierarchically tailored structure. [Display omitted] [ABSTRACT FROM AUTHOR]