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The reaction turns the =O group into a hydroxyl, and the hydroxyl into an ether bridge (−O−) between the two carbon atoms, thus creating a ring with one oxygen atom and four or five carbons. If the cycle has five carbon atoms (six atoms in total), the closed form is called a pyranose , after the cyclic ether tetrahydropyran , that has the ...
The hydroxyl groups (−OH) of cellulose can be partially or fully reacted with various reagents to afford derivatives with useful properties like mainly cellulose esters and cellulose ethers (−OR). In principle, although not always in current industrial practice, cellulosic polymers are renewable resources.
These enzymes have a variety of uses including degradation of plant materials (e.g., cellulases for degrading cellulose to glucose, which can be used for ethanol production), in the food industry (invertase for manufacture of invert sugar, amylase for production of maltodextrins), and in the paper and pulp industry (xylanases for removing ...
AKD's feature hydrophobic alkyl groups extending from a beta-propiolactone ring. A specific example is derived from the dimerization of the ketene of stearic acid. This ketene is generated by pyrolysis of stearoyl chloride. [2] AKD's react with the hydroxyl groups on the cellulose via esterification reaction. The esterification is competitive ...
In chemistry, hydroxylation refers to the installation of a hydroxyl group (−OH) into an organic compound. Hydroxylations generate alcohols and phenols, which are very common functional groups. Hydroxylation confers some degree of water-solubility. Hydroxylation of a hydrocarbon is an oxidation, thus a step in degradation.
HPC is an ether of cellulose in which some of the hydroxyl groups in the repeating glucose units have been hydroxypropylated forming -OCH 2 CH(OH)CH 3 groups using propylene oxide. The average number of substituted hydroxyl groups per glucose unit is referred to as the degree of substitution (DS). Complete substitution would provide a DS of 3.
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula −OH and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry , alcohols and carboxylic acids contain one or more hydroxy groups.
Sugar alcohols can be, and often are, produced from renewable resources.Particular feedstocks are starch, cellulose and hemicellulose; the main conversion technologies use H 2 as the reagent: hydrogenolysis, i.e. the cleavage of C−O single bonds, converting polymers to smaller molecules, and hydrogenation of C=O double bonds, converting sugars to sugar alcohols.