Influence of Organic Diluents on Cellulose Carboxymethylation

A comparative study of the influence of acetone, isopropyl alcohol and mixtures of ethanol-acetone and ethanol-isopropyl alcohol on the cellulose structure during alkalization is presented. The kinetic behavior and distribution of substituents in the carboxymethylation stage are explained tentatively. It is shown that the decrystallization is more pronounced and the proportion of cellulose I is higher for samples alkalized in ethanol-isopropanol and ethanol-acetone mixtures containing up to about 50% ethanol, as compared with those produced in isopropyl alcohol or acetone. The distribution of substituents in the C6 position, as evaluated by 1H NMR spectroscopy, is correlatedwith the change of the cellulose structure revealed by X-ray analysis data.