Biopolymer‐Based Flame Retardants and Flame‐Retardant Materials

Polymeric materials featuring excellent flame retardancy are essential for applications requiring high levels of fire safety, while those based on biopolymers are highly favored due to their eco-friendly nature, sustainable characteristics, and abundant availability. This review first outlines the pyrolysis behaviors of biopolymers, with particular emphasis on naturally occurring ones derived from non-food sources such as cellulose, chitin/chitosan, alginate, and lignin. Then, the strategies for chemical modifications of biopolymers for flame-retardant purposes through covalent, ionic, and coordination bonds are presented and compared. The emphasis is placed on advanced methods for introducing biopolymer-based flame retardants into polymeric matrices and fabricating biopolymer-based flame-retardant materials. Finally, the challenges for sustaining the current momentum in the utilization of biopolymers for flame-retardant purposes are further discussed.