Phosphorylated polysaccharides. 3. Synthesis of phosphorylated curdlan and its polyelectrolyte behaviour compared with other phosphorylated polysaccharides

A water-soluble phosphorylated curdlan (PCurd) was synthesized by reaction of curdlan with phosphorous acid in molten urea. The structure of PCurd was investigated by FTIR and NMR spectroscopy and the substitution degree was calculated from potentiometric titration. It was found that the obtained curdlan derivative is a monobasic curdlan phosphate with –HP(O)(OH) groups. The polyelectrolyte behaviour of PCurd, studied by electrochemical methods and by viscometry, was compared with other phosphorylated polysaccharides. A slight influence of the polysaccharide chain flexibility on the polyelectrolyte dissociation was observed.