From Single MOFs to Synergistic Systems: A Review on Flame-Retardant Applications

Metal-organic frameworks (MOFs) are porous crystalline materials whose metal nodes, organic linkers, and pore environments can be adjusted for a particular use. These features make them useful candidates for polymer flame retardancy. In a burning polymer, an MOF may contribute through more than one route: it can promote char in the condensed phase, adsorb volatile products, and help interrupt radical reactions in the gas phase. This review first outlines the structural features that control those effects. It then compares the reported performance of individual MOFs with that of MOF-based composite systems, including phosphorus-containing and nanomaterial-assisted formulations. The remaining limits, especially thermal stability, synthesis efficiency, and scale-up, are also considered. The aim is to connect MOF structure with the practical design of halogen-free polymer flame retardants.