Flame retardancy for cotton cellulose treated withH₃PO₃

The flame retardancy of cotton fabrics has been improved with treatment of phosphorous aqueous solution. In this study, cotton cellulose is treated with simple treatment and benign chemicals including an aqueous H 3 PO 3 solution dipping and heat annealing. The flame retardancy of the H 3 PO 3 treated cotton fabrics is enhanced to the degree that it is non‐flammable. Thermogravimetric analysis results show that the residue increased up to about 50% at 800 °C by the treatment. Scanning electron microscopy exhibit some disconnection of fibers and the fibers are fragile. X‐ray diffractometry reveal little damage to the crystalline structure of cellulose. Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy show some portion of the added H 3 PO 3 reacted with cellulose components to be phosphorylated and dehydrated. The resulting data and analysis demonstrate that these dehydrated and phosphorylated moieties formed by treatment of phosphorous solution help accelerate the formation of char components, resulting in improved flame retardancy of cellulose materials.