Recent Advancements of Bio-Derived Flame Retardants for Polymeric Materials.

The sustainable flame retardancy of polymeric materials is a key focus for the direction of the next generation in the field of fire safety. Bio-derived flame retardants are gaining attention as environmentally friendly additives due to their low ecological impact and decreasing costs. These compounds can enhance char formation in polymeric materials by swelling upon heating, attributed to their functional groups. This review explores various biomolecules used as flame retardants, including phytic acid, chitosan, lignin, tannic acid, and bio-derived phosphorus and nitrogen compounds, emphasizing their flame-retardant properties and compatibility with different polymer matrices. The primary focus is on the structural characteristics, modifications, and flame-retardant behaviors of these bio-derived additives, particularly regarding their mechanisms of action within polymeric materials. Finally, the review explores the opportunities, current challenges, and future directions for the practical application of bio-derived flame retardants in polymer materials.