CHITOSAN N-SULFATE - A WATER-SOLUBLE POLYELECTROLYTE

Chitosans having degrees of acetylation (da) of 0.04, 0.10, and 0.22, respectively, were N-sulfated under a variety of reaction conditions. The derivatives obtained ranged in degree of sulfation (ds) from 0.4 t o 0.86 (+/-0.05). All were soluble in water, and the theological prope rties of their solutions varied markedly with da and ds values. Both i onic strength and pH had an effect on their solubility properties, and also on interactions that they exhibited with O-(carboxymethyl)cellul ose, xanthan gum, and heparin. Being compatible with other polyelectro lytes such as these, the chitosan derivatives may be useful in some aq ueous formulations. (C) 1997 Elsevier Science Ltd.