Hydroxyl groups cellulose

Reducing the number of cellulose hydroxyl groups that are available for moisture pickup. 

The dissolution of cellulose and other plant-based material in ILs has been studied by Moyna and Rogers [64-66]. Here, the application of NMR excluded fhe need for solvenf suppression techniques. In combination with and C1/ C1 relaxation measurements, it was found that dissolution of cellulose in [C4CiIm]Cl was promoted by the nonhydrated chloride ions, breaking up the hydrogen bonding networks via the cellulose hydroxyl groups. 

Cellulose esters and cellulose ethers are prepared based on the substitution of cellulose hydroxyl groups with short chain regents. Cellulose can also be modified by introduction of long chain polymer(s) onto its main chain. The products are mostly grafted copolymers, and in some cases, block copolymers can also be made. 

Chemical microstructural analysis (CMA) method is based on reactivity of the cellulosic hydroxyl groups with diethylaminoethyl chloride under very mild basic conditions, which, to the best of our knowledge, does not further disrupt ordered regions. The cotton cellulose is reacted with diethylaminoethyl (DEAE) chloride as shown in Figure 5.24. 

Cellulose hydroxyl groups and the amino group of amines form a hydrogen bond which is mainly responsible for the complex formation162. 

These contain the acrylamide residue D.NH.CO.CH2 CH2 as the reactive component, D representing the chromophore-containing portion of the dye molecule. In the presence of alkali the reaction between a cellulosic hydroxyl group and the terminal CH is similar to that which has been described for the Remazol dyes... 

The comonomer complexes may be anchored on the cellulose, analogous to structures I and II, or through the interaction of zinc chloride and the cellulosic hydroxyl groups aqueous solutions of the metal halide are known to break the hydrogen bonds in cellulose and reduce crystallinity. Although radicals generated on the cellulose as the result of reaction with the catalyst may initiate polymerization of the comonomer... 

The many hydroxyl groups on cellulose provide for extensive interaction between polar macromolecules and the paper electrophoresis strip. Therefore, hydrophilic proteins and nucleic acids tend to have low electrophoretic mobility. Acetylation of the cellulose hydroxyl groups produces a medium (cellulose acetate) that greatly speeds up electrophoreses. For cellulose acetate electrophoreses O.IM barbital buffer is the standard one. 

Alkenyl succinic anhydride (ASA) may also, like AKD, either react with cellulose hydroxyl groups or with water, as shown in Figure 7.25. Note that the side reaction of ASA leads to the formation of a dicar-boxylic acid, which due to its amphiphilic nature can lower the surface tension of polar liquids, such as water, and thereby also decrease the sizing efficiency. The reactivity of ASA is claimed to be much higher than that of AKD and full sizing develops immediately in the paper machine, and suggests that covalent bonds... 

In contrast to the sulfite process, coniferous woods, sawdust, and high resin woods can be used in the sulfate process. The wood is boiled for some hours with a solution of sodium hydroxide, sodium carbonate, and sodium sulfide at 165-175° C. It is presumed that some of the cellulose hydroxyl groups are converted to sulfhydryl groups at this stage. The mercaptan groups formed are not stable in alkali and attack the ether cross-links of lignin by... 

Cellulose ethers are produced from alkali cellulose, since the alkali extends the cellulose lattice, thus increasing the accessibility to the cellulose hydroxyl groups. A distinction is made industrially between processes with and without alkali consumption. 

Strictly speaking CTA should have aD.S. of 3. However, aeeording to the U.S. Federal Trade Commission if not lesss than 92% of the cellulose hydroxyl groups are acetylated the term "triacetate" may be used. The aeetyl value, or the weight percent of ethanoate groups in the polymer, of commercial CTA for fiber production is 44.3 - 44.8% (or a D.S. of ca.3) but commercial CTA for other uses is about 40.5% (D.S. = 2.6). 

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