Flame retardancy and combustion performance of polysaccharide fabrics: A comparison on cotton and calcium alginate fabrics

Cotton and calcium alginate (CA) fibers are both polysaccharide-based fibers, but they possess different flame retardancy. The detailed comparisons on flame retardancy and combustion behavior of polysaccharide fabrics are of interest. In this study, the difference between the fabrics made of these two fibers in the combustion process, pyrolysis products and the morphology and chemical structures of char residues were performed by vertical burning, thermal gravimetric analysis, Fourier Transform Infrared Spectrometer (FTIR) and scanning electron microscopy. Compared with cotton fabric, CA fabric had no after-flame when it was burned vertically, and the smoldering time was longer. Especially, the smoke release rate, peak heat release rate and total heat release were much lower versus cotton fabric, indicating that CA fabric had much lower fire hazards than cotton fabric. The results of thermogravimetric analysis coupled with FTIR (TG-FTIR) suggested that CA fabric exhibited a different thermal degradation pathway versus cotton fabric. Under the same quality, CA fabric produced more char residues after combustion, and chrysanthemum-like calcium oxide were generated on the surface of char residues as protective barrier, leading to the enhanced flame retardancy of CA fabric.

Automated summary

This study compared the combustion process, pyrolysis products, morphology, and chemical structures of fabrics made of cotton and calcium alginate (CA) fibers. The results showed that CA fabric had no after-flame and longer smoldering time compared to cotton fabric. Additionally, the smoke release rate, peak heat release rate, and total heat release were significantly lower for CA fabric, indicating lower fire hazards. The thermal degradation pathway and char residues of CA fabric were different from cotton fabric. CA fabric produced more char residues and formed chrysanthemum-like calcium oxide on the surface, enhancing its flame retardancy.