Phosphorylated chitosan@MXene biomass-based coating with high flame retardancy and environmental friendliness for cotton fabric.

To obtain cotton fabrics with high-efficiency flame retardancy, a novel nanohybrid MXene modified with phosphorylated chitosan (CS) was successfully prepared through a simple chemical modification strategy. It was subsequently employed in the fabrication of PC@T-MXene-functionalized cotton fabric (PC@T-MXene-C) through an impregnation process. The thermal stability and flame retardancy of the pure and treated cotton textiles were analyzed via TGA, LOI, VBT flammability tests and cone calorimetry. Compared with those of the original cotton textile and PCS-decorated cotton fabric (PC-C), the thermal and flame-retardant performance of PC@T-MXene-C was significantly enhanced. When the weight gain of the treated cotton fabric was 12 % (PC@T-MXene-C3), the LOI of PC@T-MXene-C3 significantly reached 35 %, and the peak heat release rate (PHRR) and total heat release (THR) decreased by 80.7 % and 43.7 %, respectively, compared with those of the original cotton textile. Additionally, PC@T-MXene-C3 retained 39.1 % of the char residual at high temperature under a nitrogen atmosphere in the TGA analysis. This eco-friendly biomass-based flame-retardant coating provides a new strategy for fabricating green flame-retardant systems without the use of hazardous compounds.