Potentiometric Titration Behavior of Glycol-chitosan

The potentiometric titrations of glycol-chitosan (GCH) were carried out in water and NaCl aqueous mediums at the ionic strengthsμ of 0.05, 0.1 and 0.2μ with a 1N-HCl volumetric solution. And the relations between apparent dissociation constant [(PKb) app] and degree of dissociation (αd) were pursued. On the other hand, electrophoretic mobilities of GCH were measured in buffer solutions at the μ of 0.05, 0.1 and 0.2, and the relations between limiting mobility (Uc→0) and ad were pursued from Uc→0-pH curves and the potentiometric titration results. It was deduced from comparing of (PKb) app-αd curves with Uc→0-αd curves that the dissociation behavior of GCH with non-flexible chain was mainly affected by increase of polyion charges with neutralizing.