Cellulose some reactions

Jones, David M., Structure and Some Reactions of Cellulose, 19, 219-246... 

Cellulose esters of the 2-.. 3-. and 4-carbon acids are readily prepared by the cellulose-anhydride reaction the acetate ester and the mixed acetate butyrate and acetate propionate esters arc manufactured and used in large amounts. Esters of higher acids require different synthesis techniques and tend to be prohibitively expensive except as specialty products. Some arc in commercial production, however. Cellulose acclalc phlhalatc, for example, is manufactured for use as an enteric coating on pills. 

Reactions catalyzed by solid bases were obvious candidates for testing hypotheses on the nature and the mode of action of enzymes. Bredig [40] used aminated cellulose (B2) as a model because an enzyme was thought to consist of "a specific active function and a colloidal carrier". Indeed, cyanohydrin 40 was formed with an enantiomeric excess of 22% Fig. 3 and Table 3 contain a summary of the reported results for base-catalyzed reactions. It is not clear whether the ZnO/ffuctose catalyst (Bl) described by Erlenmeyer [39] is really heterogeneous but it is the first report on using sugars as modifiers. Some reactions are probably just curiosities (39, 41), but two... 

Some reactions and derivs of cellulose are given under Cellulose(above). The derivs of interest in the expl industry and allied applications are included here ... 

Figure 3 is the result of pulse radiolysis experiment about the reaction of hydrated electron with polymer chains(0 or 30 mM carboxymethyl chitosan solution with 0.3 M terf-butanol under Ar saturation), and shows the decay of the absorbance as a function of time. This absorbance was measured at wavelength 720 nm, which is the absorption peak of hydrated electron. As seen in Figure 3, the absorbance increases immediately after the irradiation, and attenuates afterwards. This means that hydrated electron is generated immediately after irradiation and diminishes gradually by some reactions of hydrated electron. Compared the absorbance decay of polymer solution with the decay of solution without polymer, the decay of polymer solution is faster than without polymer, so it is obvious that hydrated electron reacts with polymer chains. The decay curve can be fitted by pseudo first-order decay. The pseudo first-order decay is shown by equation (8). From estimating the slope of the pseudo first-order decay rate of the absorbance at 720 nm against polymer concentration, the rate constant of the reaction of hydrated electron with polymer chains can be calculated Figure 4). The rate constants of the reaction of hydrated electron with CM-chitin and CM-chitosan was determined as l.lxlO7 and MxlO M V1]. These values are almost the same with the value of carboxymethyl cellulose(2< ).

Jeffrey, G. A., and Rosenstein, R. D., Crystal-structure Analysis in Carbohydrate Chemistry, 19,7-22 Jones, David M., Structure and Some Reactions of Cellulose, 19,219-246 Jones, J. K. N., and Smith, F., Plant Gums and Mucilages, 4,243-291 Jones, J. K. N. See also. Hirst, E. L. 

Each glucose unit in a molecule of cellulose has three hydroxyl groups that can be used to derivatize the cellulose by reactions common to all alcohols. It is uncommon, and for some derivatives impossible, to achieve a degree of substitution (DS) of three. Most important derivatives of cellulose have a DS that is somewhat below that value. For a given derivative, the DS must be specified since the properties of the derivative depend almost as much on DS as they do on the substituting agent. 

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