Abstract: With the wide application of epoxy resin (EP) in modern industry, the demand for its multifunctionality and high performance has become increasingly critical. In this study, we developed an innovative multifunctional nanohybrid material, BZrP@CoSn(OH)₆, through a combination of in situ growth and ion-exchange strategies. This nanohybrid was uniformly incorporated into the EP matrix, delivering transformative improvements to its properties. At an optimized loading of 5 wt%, BZrP@CoSn(OH)₆ enabled the composites to achieve the vertical combustion test (UL-94) V0 rating, alongside notable reductions in peak heat release rate (pHRR), total smoke production (TSP), peak carbon monoxide release (pCOP), and total volatile products by 54.0 %, 48.1 %, 46.9 %, and 63.3 %, respectively. The synergistic action of zirconium phosphate and bimetallic catalysis greatly improves the residue yield, and the formation of a strong char layer acts as an effective physical barrier. The mechanical interlocked structure between BZrP@CoSn(OH)₆ and the matrix facilitated a strong interfacial bond, leading to substantial improvements in mechanical performance, with tensile strength and elongation at break increasing by 40.4 % and 63.7 %. Additionally, the nanohybrids enhanced the thermal conductivity and endowed the composite with remarkable antibacterial and ultraviolet (UV) shielding properties. This work demonstrates the synergistic effect of interface engineering and nanohybrid materials in achieving a harmonious balance between flame retardancy and multifunctionality, offering a promising strategy for the design and application of high-performance epoxy resin composites.

Key words: Multifunctional, MOFs derivatives, Epoxy resins, Flame retardancy