"ON THE IMPORTANCE OF VARIATION OF ALKALISATION CONDITIONS ON CELLULOSE ETHER SYNTHESIS"

Abstract

With a multivariate approach, we investigate and correlate the effect of mercerization conditions on the properties of a cellulose ether. We have chosen to work with carboxymethylcellulose (CMC) for analytical reasons. As expected, the DS was found to increase when the NaOH/AGU (anhydroglucose unit) stoichiometric ratio (r) was increased (range 1.0–1.3) and [NaOH] was decreased (range 50-30%). However, such changes also favoured the formation of unwanted side products. Decreased (r) and increased [NaOH] resulted in increased heterogeneity, and thus the quantities of insoluble particles and unreacted chemicals also increased. As another result, the prediction between mercerisation and synthesis weakens. Consequently, a DS of 0.18–0.7 was obtained; the measured solubility was much lower than expected. A non-statistical distribution of substituents was further found. Interestingly, the relative importance of substitution at increases with an increased [NaOH].