A Novel Reactive B/N/P-Containing Flame Retardant and Its Application on Cotton Fabrics

In this study, a water-soluble with environmental friendly flame retardant (AEPBEA) containing B, N, and P elements was synthesized using erythritol, phosphoric acid, boric acid and urea. The synthesized AEPBEA was characterized by 1H nuclear magnetic resonance (1H NMR) and Fourier-transform infrared spectrum (FTIR). The synthesized AEPBEA was coated onto cotton fabrics to increase the flame retardancy of cotton fabrics. Cotton fabrics before and after treated by AEPBEA were characterized using Fourier-transform infrared (FTIR), Scanning electron microscopy—energy dispersive X-ray spectroscopy (SEM–EDX), X-ray diffraction (XRD). The thermal stability of the samples was researched by thermo-gravimetric (TG), and the char residue rate of the treated cotton fabrics could reach 47% in the nitrogen atmosphere. The combustion behavior of cotton fabrics was evaluated by cone calorimetry, and the peak of heat release rate (PHRR) and total heat release (THR) decreased by 90.7 and 60.58% after treated by AEPBEA. The limiting oxygen index (LOI) of cotton treated with 300 g/L AEPBEA reached 43.3% and the carbon length was 4.6 cm. After 50 laundering cycles (LCs), the LOI value could still reach 29.1%. In addition, the mechanical properties of the treated cotton only decreased slightly, and could match the practical usage.