Preparation and purification of cellulose ethers

摘要

Polysaccharide ethers are made by reacting an alkali metal polysaccharide and an etherifying agent in a diluent containing a liquid hydrocarbon. The reaction mixture is subjected to azeotroping conditions which remove water and hydroxyl containing organic by-products, which interfere with cross-linking reaction of the crude polysaccharide ether with carbonyl compounds. The process is especially adaptable to water-solubilizible cellulose ethers with gel points of about 90 DEG C or higher.