Solubility of cellulose III in sodium hydroxide solution

Abstract

Studies on cellulose III solubility have been conducted in 8.5% NaOH solution with and without the presence of added substances, such as acrylamide, acrylic acid, acrylonitrile, and thiourea. The highest value of cellulose III solubility was obtained as a result of the introduction thiourea and acrylamide in a 5% ratio of NaOH into NaOH solution. Moreover, dissolving conditions proved to be of great importance. Cellulose III introduced into NaOH solution and repeatedly frozen and unfrozen three times dissolved 50% (dissolving with 5% thiourea). The soluble cellulose fraction showed significantly lower molecular mass in comparison with its insoluble fraction. Comparative studies on cellulose crystallinity using the CP / MAS ¹³C‐NMR method showed a satisfactory compatibility of results with determinations obtained from the X‐ray method. © 1993 John Wiley & Sons, Inc.