The conversion of calcium alginate fibers into alginic acid fibers and sodium alginate fibers

Alginate is a natural polymer extracted from brown seaweeds. Over the last two decades, alginate fibers have become well established in the wound management industry where their ion exchange and gel forming abilities are particularly useful in the treatment for exuding wounds. Alginate fibers are commonly made by extruding sodium alginate solution into a calcium chloride bath, producing calcium alginate fibers. To improve the gelling ability and the absorption capacity of calcium alginate fibers, this study used hydrochloric acid to convert calcium alginate fibers into alginic acid fibers, which was further converted into sodium alginate fibers by treating the fibers with sodium hydroxide in organic solvent. Results showed that alginic acid and sodium alginate fibers and fabrics can be readily made by treating the calcium alginate fibers and fabrics, respectively, with hydrochloric acid and sodium hydroxide. Improved gel blocking properties and absorption capacities were obtained with the sodium alginate fibers. (c) 2006 Wiley Periodicals, Inc.