EFFECTIVE ESTERIFICATION OF CARBOXYMETHYL CELLULOSE IN A NEW NONAQUEOUS SWELLING SYSTEM

Carboxymethyl cellulose (CMC) was treated in a dipolar-aprotic solvent like N,N-dimethylacetamide, or dimethylsulfolxide (DMSO) with p-tolue nesulfonic acid yielding a high reactive gel-suspension of the polymer . This mixture allows a direct esterification of free hydroxyl groups of CMC as exemplified by acylation with carbonic acid chlorides, or an hydrides, and with isocyanates as well as by sulphation, phosphating a nd silylation. The products characterized by elemental analysis and FT IR spectroscopy possess a high degree of functionalization.