Influence of Calcium Ion on Thermal Degradation and Flame Retardance Behaviour of Alginate Fiber

Abstract

Experimental research on calcium alginate fibers thermal degradation and flame retardancy under catalysis of metallic salts was done by limiting oxygen index (LOI), scanning electron microscopy (SEM), and thermogravimetric analysis (TG) methods. LOI results show that with increasing calcium ions content, the flame retardant properties of the calcium alginate fibers improves further. The residues of calcium alginate fibers gradually retained fiber shape and on the surface of the residues the holes reduced, with the calcium ion content increasing. TG indicates temperature at maximum rate of weight loss (T-max) was clearly shifted from 246 °C for alginic acid fibers to 244°C, 236°C, 208°C, 205 °C and 203°C (SCa-1-1# calcium alginate fibers, SCa-2-2# calcium alginate fibers, SCa-3-3# calcium alginate fibers, SCa-4-4# calcium alginate fibers, SCa-5-5# calcium alginate fibers), respectively. The thermal degradation residues at 1000°C for different calcium alginate fibers are 13.7%, 16.1%, 17.2%, 18.2%, 18.4%, 19.2%, separately. Further discussion of the combustion process and flame retardant mechanism is presented.