Study of a procedure for the obtainment of methylcellulose from mechanic pulp in homogeneous media

Abstract

The etherification reaction of mechanic pulp (MP) with dimethylsulphate (DMS) in homogeneous media was studied using a 25-1 fractional factorial experimental design. In according to this model the quantity of DMS/2 g of dissolved MP and the interaction between reaction temperature and reaction time were established as reaction critical factors. The results obtained under different reaction conditions showed a low mass yield (around of 20%) and a low percentage of methoxylation (%MeO) (around of 0.5%). The reasons that could explain this low performance of reaction would be a low NaOH solubility in the mixture solvent dimethylacetamide - lithium chloride (DMAc/LiCl) which would produce a poor cellulose activation, and the heterogeneous composition of MP which contains besides cellulose, hemicelluloses and lignin, which also could react with DMS.