Cellulose reaction

Schwenkkr, R. F., and E. Pacsu Graft polymerization onto cellulose reactions of sodium cellulosate and alkali cellulose with vinyl monomers. Tappi 46, 665 (1963). 

Timell, T. (1950). Studies on cellulose reactions. Ph.D. Thesis, Univ. of Stockholm, Stockholm. 

Reaction (1) is rapid and occurs under mild conditions, hydrolyzing mainly the hemi-celluloses. Reaction (2) is slow, proceeds as a first-order reaction, and is the limiting reaction in this process. Reaction (3) is rapid. 

The surface of crystallites also represents a portion of the cellulose component readily accessible to chemical agents. Thus, the nature of crystallite surface along with crystallinity influences the apparent accessibility of cellulose, especially when measured by chemical reactions. Among major polymorphs, cellulose I and II are most important in cellulose reactions. 

Sulfuric acid is a powerful esterification catalyst. It has been widely applied with mixtures of acetic acid and acetic anhydride to promote acetylations of numerous substances. Use of this catalyzed reaction for starch acetylation, however, has not risen to pre-eminence among starch acetylation methods as it has done among cellulose acetylations, although both reactions were discovered at the same time. The underdevelopment of this reaction in the starch field may be due to the following causes (1) sulfuric acid, a powerful acetylation catalyst, strongly catalyzes the hydrolysis of starch molecules and cannot be used for starch acetylations in the concentrations found most effective for cellulose reactions (2) most investigations of this reaction have been made on whole granules... 

Cellulose Reactions Pertinent to the Formation of the Chromophore of the Shroud Body-Only Image... 

Cellulose Reaction with Formaldehyde and Its Amide Derivatives... 

Although not a measure of cellulose crosslinking, since mono functional agaits are incapable of crosslinking, the response to hydrolysis conditions of cotton fabric treated with N-methyl, N -hydroxymethylethyleieurea offers evidence of cellulose reaction. This response can be seen in Table II. Formaldehyde is released from the... 

The purpose of this chapter is to describe exploratory 13C-NMR studies of formaldehyde-cellulose reaction model systems. Solid state NMR spectra are still comparatively broad and do not reveal as much detail as solution spectra Ql). Furthermore, solid state NMR studies are still cumbersome, ana since no references are available on solid state studies of cellulose-formaldehyde interactions, we conducted an analysis of model systems for cellulose that are water soluble. This paper reports reactions of formaldehyde with methanol, ethyIenegIycoI, some seIect sugars, and ceI Iobi ose. 

Amide derivatives, cellulose, reaction with formaldehyde and its, 52... 

T. E. Timell, Cellulose reactions. I. A method for the determination of the distribution of the substituents in the glucose residues of a partly substituted methylcellulose, Sv. Papperstidn., 51 (1948) 52-56. 

As noted above, prior to the development of the LiCl/DMAC cellulose solvent, permitting a homogeneous cellulose reaction medium, all cellulose reactions were heterogeneous in nature, at least initially, due to the two-phase nature of cellulose. That is, solid cellulose is composed of crystaline and disordered regions. The determination of the crystallinity of a cellulose sample will not be treated here. The interested reader is referred to T ripp s paper (9). 

In the case of a merely intermicellar reaction, even when taking place in a swollen gel, a substitution reaction will only reach certain sections of the chains and will leave other sections entirely unaffected. Several cases of this kind have been investigated, but they have often been otherwise and incorrectly interpreted Some very elucidating cases have been reported by Centola in cellulose reactions. 

Hydroxyethylcellulose (HEC) and hydroxypropylcellulose (HPC) are prepared by nucleophilic ring opening of ethylene oxide and propylene oxide, respectively, by the hydroxyl anions on the anhydroglucose ring of cellulose. Reactions are conducted commercially in caustic aqueous slurry processes (72). Laboratory methods recently have been reported for preparation of cellulose ethers, esters, and carbamates imder homogeneous reaction conditions in organic solvents (88-91). Such solvents may lead to development of new commercial processes for cellulose derivatives with more imiform substitution. 

Reaction with a 2-amino-4,6-dichloro-s-triazinyl derivative of DEAE-cellulose Reaction with s-triazinylated DEAE-cellulose... 

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