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.