ZIF-67-driven synergistic strategies for high-performance flame retardant polymer nanocomposites

Polymers are valued in numerous critical applications due to their lightweight nature, ease of processing and affordability. A major drawback is their natural flammability, which poses a serious risk, as combustion is often accompanied by intense heat release, molten drips and toxic smoke, all of which can easily lead to fire hazards. Traditional flame retardants, such as phosphorus-based compounds, clays and carbon-based materials, often suffer from drawbacks including poor dispersion, weak compatibility with polymer matrices and low char-forming efficiency. ZIF-67, as an important member of metal-organic framework (MOF) materials, has become a promising alternative owing to its exceptional specific surface area, regular pore configuration and cobalt-based catalytic sites. These characteristics enable ZIF-67 to form multi-scale composite systems with various flame retardants, thereby overcoming the individual limitations of each. Building on these unique properties, significant research efforts have focused on integrating ZIF-67 with various flame retardants to create high-performance hybrid systems. This review article provides a detailed overview of strategies for combining ZIF-67 with diverse categories of fire retardants and analyzes the resulting enhancements in fire resistance across various polymer matrices. In addition, this review addresses the prospects and ongoing challenges regarding the advancement of ZIF-67-based flame retardant systems.