Determination of the viscometric constants for chitosan

The viscometric constants a and K_m in the Mark-Houwink equation have been determined for chitosan in 0.1 m acetic acid 0.2 m sodium chloride solution, using the approach of Sharples and Major. The number-average molecular weights were determined by absorbance measurements on solutions of the phenylosazone derivatives. The values obtained a = 0.93, K_m = 1.81 × 10^?3 cm³ g¹ differ considerably from those reported previously by Lee but are in agreement with values found for other ionic polysaccharides having related β-(1 → 4)-linked structures.