STUDIES ON SULFATION OF PARTIALLY SUBSTITUTED CELLULOSE-ACETATE UNDERHOMOGENEOUS REACTION CONDITIONS

This contribution summarizes our results on the homogeneous sulphation of commercial cellulose acetates (DS approximately 2 and 2.5, resp.) with different acylation agents in dimethylformamide as the reaction m edium. After deacetylation with NaOH in ethanol, water-soluble Na-cell ulose sulphates were generally obtained at a DS of sulphate half ester groups exceeding 0.25. The acylation agent employed (SO3, ClSO3H, Ole um, SO2Cl2, H2NSO3H and CH3COSO4H) was of influence mainly on the reag ent yield and product viscosity. The maximum DS of sulphate half ester groups is limited by the amount of free cellulose OH-groups, obviousl y no transesterification of acetyl groups occurring.