Facile synthesis of bio-based phosphorus/nitrogen compound for high efficiency flame retardant finishing of cotton fabric

The high flammability of cotton fabric limits its wide application in interior decoration and clothing. In this work, a phosphorus/nitrogen compound named chitosan modified ammonium polyphosphate (CS@APP) was facilely prepared by mechanochemical strategy and used for flame retardant finishing of cotton fabric (CF). The characterization results showed that CS@APP was successfully synthesized through the –NH 3 + –O − P– bond. The CF with CS@APP showed remarkable reductions of 88.7% and 61.3% in peak heat release rate (pHRR) and total heat release rate than CF. Also, the limiting oxygen index of flame retardant CF reached 53.5%, and the damaged length during the vertical flammability test was 84 mm. The flame-retardant mechanism was speculated on char residues and pyrolysis gas. The work provides new sights on the facile synthesis of phosphorylated chitosan and explores a new way to the utilization of biological resources. Graphical abstract