Carboxymethylation Of Cellulose Research Articles

Solvent effect on carboxymethylation of cellulose

The relationship between the composition of the solvent (water/isopropyl alcohol) and the degree of substitution, viscosity and molecular weight of carboxymethylcellulose (CMC) is investigated. It is found that the alcohol facilitates the destruction of cellulose crystalline structure and the diffusion of the small reagent molecules into the cellulose, which elevates the availability of the reagent for etherification. Because of the weak polarizability of isopropyl alcohol, it helps to keep the the cellulose molecules to be less decomposed by alkali. This results in the increase of the degree of substitution for the CMC and effects the CMC's high resistance to alkali

Kinetics of the carboxymethylation of cellulose in the isopropyl alcohol system

AbstractThe carboxymethylation of original and activated cellulose in the system cellulose/NaOH/isopropyl alcohol/CH2ClCOOH has been investigated by means of conductometry, viscosimetry and X‐ray diffractometry. It has been found that the carboxymethylation process in this system is a pseudo‐first‐order reaction with two stages having different first‐order rate constants. By application of the activation method the rate of etherification and the utilization ratio of the etherifying agent were increased and the quality of the product was improved.

Repetitive carboxymethylation of cellulose

AbstractRepetitive carboxymethylation enhances the degree of substitution of cellulose obtained from jute fibre, cotton and wood pulp. The extent of increase in the degree of substitution depends on the type of the cellulosic source. Although introduction of carboxymethyl groups resulted in products with fairly high degrees of substitution, it was foud that during the process of carboxymethylation the molecular mass of the starting material undergoes substantial degradation.