Chitosan processing: influence of process parameters during acidic and alkaline hydrolysis and effect of the processing sequence on the resultant chitosan's properties

The objectives of this study were to investigate the influence of reaction temperature, processing time, and mechanical shear on the depolymerization (DP) of chitosans and to evaluate the importance of the sequencing of the d eacetylation and DP processes on the resultant macromolecules and their pro perties. Process sequence did not alter the degree of deacetylation (DD), t he intrinsic viscosity, or the molecular weight (MW). Treatment conditions affected the properties of the resultant polymer: the reaction temperature and processing time had a significant impact on the MWs and DDs of the resu ltant polymer. Mechanical shear, however, did not significantly affect the above properties. Furthermore, polymer crystallinity was affected by reacti on temperature but not by shear or processing time. (C) 1999 Elsevier Scien ce Ltd. All rights reserved.