Novel cellulosic ethers with low degrees of substitution¯¯II. Magic angle spinning NMR study

Magic angle spinning and cross polarisation magic angle spinning solid state 13C NMR were used to study cellulose ethers with low degrees of substitution prepared in alkaline suspension using 1-iodo- or 1-bromoalkane as the alkylating reagent, and also the parent cellulose. The spectra, recorded under high resolution conditions, revealed both the amount and the type of crystallinity in the carbohydrate and aliphatic sequences. The cellulose crystallinity appeared to be modified more by the length of the alkaline treatment and the presence of water in the solid than by the number of side chains. The relaxation time measurements clearly revealed alkyl chain interactions and gave a rough indication of the dimension of the homogeneous hydrocarbon phase domains.