An Eco-friendly Way to Improve Flame Retardancy of Cotton Fabrics: Layer-by-Layer Assembly of Semi-biobased Substance

The objective of the present study is to develop a renewable and environmentally benign technique to improve the flame retardancy of cotton fabrics by the layer-by-layer deposition of semi-biobased substances onto the surface of cotton fabrics. The used semi-biobased substances included negatively charged ingredients: phosphorylated poly (vinyl alcohol) (PPVA) and positively charged ingredients: chitosan. Some typical combustion tests, including vertical flame tests and microscale combustion calorimeter were mainly used to measure the fire safety of coated cotton fabrics. The cotton fabric assembled with 30 bilayers can extinguish flame in the vertical flame test. The reduction in peak heat release rate and total heat release could be observed for all coated cotton fabrics compared with that of pure cotton fabrics. Additionally, the thermal stability of cotton fabrics was also discussed by thermogravimetric analysis. The result indicated that thermal stability of coated cotton fabrics were enhanced in the high temperature range (400–700 ∘C).