Emerging Roles of Metal–Organic Frameworks as Flame Retardants: Recent Advances and Future Perspectives in Thermoplastic Polymers

Highlights: What are the main findings? Flame-retardant metal-organic frameworks (MOFs) have attracted growing interest in polymer applications, with substantial research progress achieved. Studies on thermoplastic polymers, despite their widespread use and large consumption, remain relatively limited and comprehensive reviews are still scarce. Six representative thermoplastic matrices have been identified for evaluations: polypropylene (PP), thermoplastic polyurethane (TPU), polylactic acid (PLA), polycarbonate (PC), polyethylene terephthalate (PET), and polystyrene (PS). The current research status of flame-retardant MOFs in these thermoplastic polymers is systematically summarized and analyzed. Existing challenges and future development prospects are discussed to provide guidance for the design and development of MOF-based flame retardants. What are the implications of the main findings? Flame-retardant MOF plays an alternative to traditional retardants. Thermoplastic application gap identification fills knowledge void, guiding academia and industrial translation. Summary of six thermoplastics guides research, accelerating commercialization. Metal–organic frameworks (MOFs), assembled from inorganic metal centers (metal ions or clusters) and organic ligands, possess distinctive features such as structural designability, high surface area, and tunable functionalities. In the past decade, MOFs have displayed substantial merits when utilized as innovative flame retardants in the realm of polymeric materials. A current focus is on the flame-retardant effects of MOFs in thermosetting plastics, yielding substantial achievements; however, systematic investigations into thermoplastic polymers, which are more widely used, remain limited. The flame-retardant mode of action for miscellaneous types of MOFs and their applications in polymeric matrices, with particular emphasis on recent advances in thermoplastic systems, are summarized. Furthermore, existing challenges and future perspectives are identified.