Distribution of Substituents in Cellulose Ethers Prepared in Aqueous and Non-Aqueous Systems

The distribution of substituents in partially substituted cellulose ethers (methyl-, carboxymethyl-, benzyl- and methallylcelluloses) prepared in aqueous and non-aqueous systems was studied. The reactivity order of three hydroxyl groups in cellulose in aqueous systems was HO-2>HO-6>HO-3 with the exception for benzylation. On the other hand, the reactivity order was HO-6>HO-2_??_HO-3 for etherifications with powdered sodium hydroxide and etherifying reagents except iodides in a non-aqueous cellulose solvent, SO2-diethylamine-dimethylsulfoxide system. The difference in reactivities of the hydroxyl groups in the non-aqueous system were much smaller than those in aqueous systems.