Environmentally benign flame-retardant cotton fabric with superior anti-wrinkle performance and restorable flame retardancy

Flammability and wrinkling are major defects that enormously restrict its application of cotton fabric in daily life. Herein, a N-heterocyclic compound with ammonium phosphate ester groups (PNH) was synthesized and served as a cross-linking agent to simultaneously enhance the flame-retardant and anti-wrinkle properties of cotton fabric. Fabric treated by 20 wt% PNH solution (CT/PNH20) possessed a wrinkle recovery angle of 234.8 degrees and an LOI value of 42.7 %. It still self-extinguished during combustion even after 50 washing times, and the deterioration in flame retardancy mainly resulted from the formation of sodium phosphates during washing. Its LOI value after 50 washing times restored to 37.8 % from 27.5 % by a facile ion exchange strategy, revealing remarkable flame-retardant restorability. This work provides new insights into simultaneously enhancing the flame-retardant, anti-wrinkle performances of cotton fabric and restoring the flame retardancy of treated fabric after washing via facile and eco-friendly approaches.