| The flammability characteristics, thermal stability and pyrolysis products of divalent metal alginate fibers, chitin fibers and alginate blend fibers made by wet spinning have been studied by LOI, CONE, SEM, TG, and PY-GC/MS tests.Combustion behaviors was assessed using the limiting oxygen index (LOI) and cone calorimetry. The incoporation of metal ions increased the LOI value and enhanced the flame retardancy of metal alginate fibers. SEM images of the residue crusts after CONE indicated that metal alginate fibers residue crusts were thicker and more consistent than the crust formed with alginic acid fiber. TG results have shown metal ions introduction enhanced the char formation, as compared to alginic acid fiber. We proposed metal ion flame retardancy mechanism for the alginate fibers.The flame retardancy and thermal stability of chitin fiber were superior to those viscose fiber. This result indicated that chitin fiber was intrinsically flame-retardancy fiber. We propose gas phase and solid phase flame retardancy mechanism for chitin fiber.As an flame retardant, nano-aluminum was widely used in plactics. Calcium alginate fiber and nano-aluminum hydroxide/calcium alginate fiber have been prepared by wet spinning process. The result showed that the strength of nano-aluminum hydroxide/calcium alginate fibers have been greatly enhanced because of the existence of the nano-alumina hydroxide particles. Thermal gravimetric analyzer test showed that the thermal stability of the composite fiber was superior to that of calcium alginate fiber. |