Polymer Bulletin, Vol.53, No.4, 243-248, 2005
Homogeneous hydroxyethylation of cellulose in NaOH/urea aqueous solution
The 6 wt.% NaOH/4 wt.% urea aqueous solution was proved to be an aqueous nonderivatizing solvent for cellulose by C-13 NMR. O-(2-hydroxyethyl) cellulose (HEC) was prepared by a totally homogeneous hydroxyethylation of cellulose using this new solvent for the first time, and the distribution of substituents within anhydroglucose units (AGU) was examined by C-13 NMR. It was found that the relative reactivity of the hydroxyl groups within AGU and the new hydroxyl group was in the order C-x > C-6 > C-2 > C-3, an analogous functionalization pattern as HEC obtained by the heterogeneous slurry process. The ethylene oxide efficiency in this homogeneous etherification reaction was 20 - 30%.