Etherification of cellulose

Various ether derivatives of cellulose, including some that are water-soluble, are important [Heinz and Liebert, 2001 Just and Majewicz, 1985 Zhang, 2001]. Methyl cellulose and car-boxymethyl cellulose (R = CH3 and CH2COOH, respectively) are synthesized by reaction of cellulose with sodium hydroxide followed by the appropriate alkyl halide  

Hydroxyethyl cellulose is produced by using ethylene oxide in place of the halide. Applications for these products include lacquers, additives for detergents, food, drilling muds, and paints. 

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Hydroxy- propyl hydroxypropyl cellulose/polysacch. by etherification of cellulose from plants emulsifier for cosmetics... 

Hydroxyl Reactivity. Tables 5 and 6 summarize the relative reactivities of hydroxyl groups observed in partial etherification of cellulose. Besides a distinctly high selectivity of the C6 OH group in tritylation, the relative reactivity of the 2-OH and 6-OH groups was considerably affected by the alkylation conditions, such as fiber swelling and the nature of etherifying conditions. 

Etherification of Wood. Etherification of wood involves the derivatization of hydroxyl groups to other functional groups. In general, etherification of wood produces more stable bonding and generates lower heat of reaction than esterification. Swelling of wood and formation of sodium salt are commonly applied as a pretreatment prior to etherification. Benzylation, cyanoethylation, allylation, and/or hydroxyethylation are commonly used in the etherification of wood. Some methods of etherification of cellulose may also be applied to wood. 

All esterification processes with acetic anhydride yield the fully esterified ester as the first soluble product. If the reaction medium is a solvent for the triester a solution is obtained, and if a reaction which retains the fiber structure is employed, samples taken at intervals are all insoluble in solvents until complete esterification is attained. The process in this way differs from nitration, in which soluble, partially esterified products are obtained by adjustment of the concentration of the nitration acids. In the etherification of cellulose, the ethers (e.g., methylated cellulose) prepared by partial substitution are also soluble products, exhibiting continuous, gradual changes in solubility characteristics with increasing substitution. 

Manufactured by etherification of cellulose with ethyl chloride. Properties Spherical particles, average diameter 340 nm [2693]. 

Previous articles in this Series dealt with etherifications of cellulose, and an atlas on infrared analysis includes spectral data for various cellulose ethers. The preparation and industrial importance of starch ethers have been reviewed. The degree of substitution of cellulose ethers may be determined by differential thermal analysis. Where an endothermic or exothermic peak that is characteristic of the cellulose derivative occurs in the analysis curve, the peak height and area have been shown to correlate with the degree of substitution. 

Etherification of cellulose proceeds under alkaline conditions, generally in aqueous NaOH solutions. Treatment of native cellulose with NaOH causes the cellulose to swell, which makes it more... 

Cyanoethylation. One of the earliest examples of etherification of cellulose by an unsaturated compound through vinyl addition is the cyanoethylation of cotton (119). This base-catalyzed reaction with acrylonitrile [107-13-1], a Michael addition, proceeds as follows ... 

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