A novel composite coating containing P/N/B and bio-based compounds for flame retardant modification of polyester/cotton blend fabrics

Herein, a novel composite coating containing P/N/B and bio-based compounds was developed and applied to the flame-retardant finishing of polyester/cotton (T/C) blend fabrics. The flame-retardant coating was prepared with a combination of triethanolamine borate , diethylenetriamine pentamethylene phosphonic acid and calcium alginate . The combined characterization of scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) proved that the coating system has been successfully processed to the surface of T/C blend fabrics. The results of limiting oxygen index (LOI), horizontal flammability test (HFT) and vertical flammability test (VFT) showed that the P/N/B/Ca-T/C blend fabrics obtained good flame retardancy and exhibited excellent char-forming ability. Meanwhile, the thermal stability and combustion behavior of the blend fabrics before and after coating were evaluated by thermogravimetric (TG) and cone calorimetry tests. Obviously, the flame-retardant coating transformed the thermal degradation process of T/C blend fabrics and suppressed their heat and smoke release during combustion. Furthermore, Fourier transform infrared (FTIR) spectroscopy of char layers and thermogravimetric-Fourier transform infrared spectroscopy (TG-IR) analysis indicated that the composite coating exerted flame retardancy to T/C blend fabrics in both the condensed and gas phases.