Aqueous green one-pot preparation of highly efficient bioderived flame retardant with favorable interfacial compatibility for polylactic acid

The highly efficient bio-based flame retardant with favorable interfacial compatibility is crucial for a polylactic acid (PLA) composite with well-balanced flame retardant and mechanical properties. In this study, a highly efficient flame retardant TPBC, hybridizing with 3-aminobenzeneboronic acid (3-ABBA), phytic acid (PA), chitosan (CS) and isocyanuric acid triglycidyl ester (TGIC), was prepared by aqueous green one-pot method. TGIC promotes uniform dispersion of the flame retardant and robust interfacial adhesion by lowering the interfacial tension and the reaction of the epoxy functional groups with the PLA terminal groups. PLA composite containing only 3 wt% TPBC exhibits a LOI value of 29.5 %, achieving the desired UL-94 V-0 rating, excellent self-extinguishing performance and a significant reduction in melting droplets. Meanwhile, the mechanical strength of 3 %TPBC-PLA is notably strengthened to be 58.1 MPa due to the boosted interfacial compatibility and the enhanced crystallinity of 21.6 %. Furthermore, the UV protection factor (UPF) of 3 %TPBC-PLA is raised to 74.7, which shows good UV shielding ability. The present work opens up a great promise for the application of the flame retardant PLA composites with high mechanical performance.