The viscosity properties of diluted and moderately concentrated chitosan solutions in water solutions of acetic and hydrochloric acids have been investigated. It has been found that there exists a narrow interval of acid concentrations where the viscosity anomaly degenerates. By using viscosimetry, a helix-coil conformational transition of chitosan macromolecules at the change of acid concentration has been established. It has been shown that the conformation of macromolecules makes an essential impact on the efficiency of reactions with chitosan, as exemplified by the production of its oligomers by means of polyglucosamine radical destruction.
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