Design of 2d charring-foaming agent for highly efficient intumescent flame retardant polylactic acid composites

In this work, a special synthetic process of charring-foaming agent nanosheet (2d-CFA) creates soft and smooth tactility, no granule with a soft quality of extension. This well-designed 2d-CFA matches well with ammonium polyphosphate (APP) to form intumescent flame retardant (IFR), obtaining well-pleasing carbonization ability, fire safety, and mechanical properties for polylactic acid (PLA) composite. 2d-CFA can reduce the flammability of the composites by forming a physical barrier against heat and mass transport under early pyrolysis of PLA. Furthermore, heat, CO, and CO₂ production in PLA composites are significantly decreased by loading low IFR. The mechanisms of enhanced carbonization ability and fire safety for PLA by loading 2d-CFA/APP are proposed based on gaseous and condensed phase products. This novel and facile modification method provides a new strategy for improving the flame retardant efficiency of IFR.