Cellulose dissolution in lithium chloride/N,N-dimethylacetamide solvent system: Relevance of kinetics of decrystallization to cellulose derivatization under homogeneous solution conditions

Rate constants and activation parameters for decrystallization of Avicel PH -101 cellulose, and bagasse-based cellulose in presence of LiCl/N,N-dimethy lacetamide solvent system have been determined from dependence of the index of crystallinity of cellulose, Ic, on time, under nonisothermal conditions . Calculated rate constants and activation parameters are negligibly depend ent on the degree of polymerization of the natural polymer. Under experimen tal conditions used, derivatization of cellulose can be started after 3 h o f cellulose-solvent contact. The relevance of our results to the industrial application of derivatization under homogeneous solution conditions is dis cussed. (C) 1999 John Wiley & Sons, Inc.