biostudies-literatureUnknown15(55)Thi NHA novel hybrid flame-retardant system, named MOF-DOPO, was developed by chemically grafting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) to an Fe-based metal-organic framework (Fe-MOF-NH₂). The combination of MOF-DOPO and urea-melamine-formaldehyde microencapsulated ammonium polyphosphate (APP@UMF) markedly enhanced the fire resistance of epoxy resin. Comprehensive analyses indicated a synergistic flame-retardant mechanism between MOF-DOPO and APP@UMF operating in both gas and condensed phases. In the gas phase, phosphorus-centered radicals from DOPO effectively captured flame-propagating radicals, while nonflammable gases (NH₃, CO₂, H₂O) diluted and cooled the combustion zone. In the condensed phase, a compact intumescent char reinfRSC advances47587-47600https://www.ebi.ac.uk/biostudies/studies/S-EPMC12679558biostudies-literatureDOPO-functionalized Fe-based metal-organic framework and its synergistic flame retardant effect with microencapsulated ammonium polyphosphate in epoxy composites.PMC12679558Tran DLOanh HTDoan TDHoang MHThi NHTran Nguyen HVan Nguyen TLe Nhat Thuy GNguyen HTfalseDOPO-functionalized Fe-based metal-organic framework and its synergistic flame retardant effect with microencapsulated ammonium polyphosphate in epoxy composites.A novel hybrid flame-retardant system, named MOF-DOPO, was developed by chemically grafting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) to an Fe-based metal-organic framework (Fe-MOF-NH₂). The combination of MOF-DOPO and urea-melamine-formaldehyde microencapsulated ammonium polyphosphate (APP@UMF) markedly enhanced the fire resistance of epoxy resin. Comprehensive analyses indicated a synergistic flame-retardant mechanism between MOF-DOPO and APP@UMF operating in both gas and condensed phases. In the gas phase, phosphorus-centered radicals from DOPO effectively captured flame-propagating radicals, while nonflammable gases (NH₃, CO₂, H₂O) diluted and cooled the combustion zone. In the condensed phase, a compact intumescent char reinf2025-01-01T00:00:00Z2025 Nov2026-06-05T23:24:38.376Z2026-05-23T03:13:07.585ZS-EPMC126795584135672310.1039/d5ra07990j