Metal-organic frameworks and their derivatives for sustainable flame-retardant polymeric materials

Biomass resources are natural polymeric materials that are abundant, affordable, non-toxic and renewable. Although they find diverse applications in both everyday life and high-tech materials, their use is often constrained by the associated fire hazards. To address this issue, there is a growing interest in the development of flame-retardant biomass polymeric materials. Metal-organic frameworks (MOFs) consist of transition metal species, flame-retardant elements and potential carbon sources, allowing for easy adjustment of their structure and properties. This versatility makes MOFs and their derivatives and hybrids highly attractive for flame retardancy studies. Despite their distinctive properties, MOFs alone may not fully satisfy the demands of commercial flame-retardant applications. The combination of MOFs with biomass materials has been identified as a promising strategy for developing efficient flame-retardant biomass nanocomposites. This innovative approach aims to address the limitations of MOFs by capitalizing on synergistic effects. This review highlights recent advancements and strategies in MOF-based flame retardants incorporating biomass materials, and it elucidates the flame-retardant mechanisms of MOF/biomass nanocomposites to inform future design efforts in the field. Furthermore, the review discusses the current challenges and prospects in this field, aiming to provide a succinct yet comprehensive overview for researchers to quickly grasp the latest developments.