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Molecular weight manipulation of chitosan I: kinetics of depolymerization by nitrous acid

✍ Scribed by G.Graham Allan; Mark Peyron

Publisher: Elsevier Science
Year: 1995
Tongue: English
Weight: 761 KB
Volume: 277
Category: Article
ISSN: 0008-6215
DOI: 10.1016/0008-6215(95)00207-a

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✦ Synopsis

The kinetics of the depolymerization of chitosan in dilute aqueous HCl solutions by nitrous acid were studied. The rate of depolymerization is independent of the molecular weight of chitosan, first order with respect to the concentrations of both nitrous acid and glucosamine moieties, not catalysed by either hydrogen or chloride ions, and Arrhenius temperature dependent. Chitosan exhibits significantly decreased reactivity as the degree of deacetylation of the polymer increases. These results are consistent with a depolymerization reaction mechanism in which the rate-limiting step is nitrosation of the unprotonated amine by nitrous acidium ion.

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