Toward Flame Retardancy, Antimelt Dripping, and UV Resistance Properties of Polylactic Acid Based on Eco-Friendly Core–Shell Flame Retardant

Abstract

To enhance the flame retardancy of polylactic acid (PLA), the exploration of bioderived flame retardants has captured the focus of researchers globally. Herein, a core−shell bioderived flame retardant is prepared through electrostatic self-assembly using ammonium polyphosphate (APP) as the core and chitosan (CS)/ tannic acid (TA) bilayer as the shell. In addition, the Fe 3+ ion is introduced into the outermost TA shell through coordination with the phenolic hydroxyl group, which can reduce the droplets during combustion.