CARBOXYMETHYLATION OF COTTON LINTERS BEFORE AND AFTER OXIDATION

Cotton linters were first purified th en subjected to oxidation reacti on using different concentration's of sodium hypochlorite. The purifie d cotton linters and the oxidized celluloses derived thereof were carb oxymethylated under identical conditions. Results obtained indicated t hat the degree of substitution (DS) of carboxymethyl cellulose (CMC) i s determined by the extent of the oxidation reaction; DS decreases as the extent of oxidation increases. The extent of oxidation was determi ned by chlorine consumption, copper number and carboxyl content. Paste s of all CMC samples exhibited non-Newtonian pseudoplastic characteris tics. At a constant rate of shear, the apparent viscosity of these pas tes decreases by increassing the extent of oxidation as well as the ra te of shear.