Preparation of MBenes and biomass MOF hybrid flame retardant through electrostatic interaction for enhancing the flame retardancy and smoke suppression performance of epoxy resin

MXenes was an emerging two-dimensional layered nanomaterial, but its flame retardancy in epoxy resins remained limited. In this study, a metal-organic framework (MOF) was synthesized from biomass-derived adenine, 3,5-pyrazole-2-carboxylic acid, and Ni²⁺ ions. After modification with hexachlorocyclotriphosphazene, it was combined with MBenes nanosheets through electrostatic interactions to synthesize bio-based organic-inorganic hybrid flame retardants (PMOF@MB), and apply it to EP. Remarkably, incorporating only 1 wt% PMOF@MB reduced the peak heat release rate (PHRR), total heat release (THR), peak CO production (PCOP), and peak CO₂ production (PCO₂P) of the EP composite by 56 %, 30 %, 62 %, and 62 %, respectively, compared to pure EP. The NiO and NiMoO₄ produced after PMOF@MB combustion catalyzed CO oxidation, formed a protective char layer, suppressed heat and toxic smoke generation, and consequently enhanced the fire resistance of EP. This work provided theoretical support for the preparation of low additive flame retardant and environmentally friendly EP composites.