An eco-friendly B/P/N flame retardant for its fabrication of high-effective and durable flame-retardant cotton fabric

High-effective and eco-friendly flame retardants have been drawing more and more attention. Herein, an eco-friendly B/P/N flame retardant (BPNM) was synthesized by esterification of phosphorylated meglumine and boric acid, and then ammoniated by urea. The flame-retardant cotton fabric of high-efficiency and durability was fabricated by durable dipping-padding treatment. The results showed that the optimal preparation condition of BPNM were at the molar ratio of meglumine to boric acid 1:4 at 130 °C for 2 h. B/P/N elements of BPNM accounted for 35.73%. The limit oxygen index (LOI) of BPNM cotton fabric reached the maximum 40.1% and was 2.2 times higher than that of the pristine fabric. BPNM cotton fabric exhibited no after-flame time and after-glow time. Compared with the untreated fabric, peak heat release rate, total heat release rate, and CO 2 /CO of BPNM cotton fabric decreased by 6.6 times, 48%, and 10 times, respectively. BPNM cotton fabric gathered the gas phase and the condense phase flame-retardant mechanism. After 30 laundry cycles, LOI of BPNM cotton fabric still maintained at 30.5%.