Cross-Linking of Cellulose

Cellophane is prepared by pressing the viscose through a narrow slit into an acid bath to form thin sheets. 

After impregnation of the cellulose substrate with an aqueous solution containing urea-formaldehyde precondensates and subsequent short heating at 130°-160°C, cross-linking takes place  

Such a treatment of fabrics ( finishing ) results in improved dimensional 

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Levin M, Handbook of Fiber Science and Technology Vol. II. Chemical Processing of Fibers andFabrics. Functional Finishes Part A,Chnpters 1 (Cross-linking of cellulosics) and 2 (Cross-linking with formaldehyde-containing reactants). New York, Marcel Dekker, 1983. 

Crosslinking Agents for Nitrocellulose The cross-linking of cellulose its derivs is mentioned briefly by Oct (Ref 3). Jullander Blom-Sallin (Ref 2) studied the crosslinking of NC by means of TiCl ... 

Dicarboxyl ic Acid Halogen Amides, Their So Its and Use in Cross-Linking of Cellulose Fibers Thru Urethone Formation. This problem was investigated by Eckert et al (Ref), who isolated some expl products. For example, N,N,N f -Tetrachloroadipumide or N,N,n n ... 

Xylan-based polymers show no convincing evidence for molecular interaction with, or cross-linking of, cellulose under the high dilution fermentation conditions. Whether this is also true in the less dilute cell wall environment remains to be determined. Description of hemicellulose polymers as glucan-binding may therefore not always be accurate. 

C.Q. Yang. Infrared spectroscopy studies of the effects of the catalyst on the ester cross-linking of cellulose by poly(carboxylic acids). J. Appl. Polym. Sci., 1993, 50(12), 2047-2053. 

W. M. Corbett and D. Winters, Cross-linking of cellulose and its derivatives. fV. Action of hydrazine on the />-toluenesulfonates of di-O-isopropylidene-D-galac-tose and -D-fructose, J. Chem. Soc., (1961) 4823 826. 

Hydrocelluloses are produced by the hydrolytic degradation of celluloses. They are similar to )8-celluloses and are also referred to as microcrystalline celluloses. If 5% of these degraded celluloses (degree of polymerization 100-200) is beaten into water with rapid stirring, a creamy substance is produced that is used in the foodstuff industry as a nondigestable thickener. The creamy consistency arises because of physical cross-linking of cellulose crystallites. 

For some specific applications (for example, thermal insulation), making mesoporous cellulosic aerogels is of high interest. One of the approaches is cross-linking of cellulosic species. Because cross-linking of cellulose is necessary to be performed in heterogeneous media (mainly with formaldehyde [56], carboxylic acid [57] or epichlorohydrin [58]), one... 

Figure 10.27. N2 srapti isotherms of cellulose acetate-based aerogels coming from supercritical CO2 drying of gels synthesized in extra-dry acetone by cross-linking of cellulose acetate (with a DP of 190) with P-MDI under dibutyltin dilaurate catalysis (at 8 g/1)- Cellulose acetate concentration in solution is maintained constant ( 80 g/1) while the cross-linking ratio (C/T) is varied [22].

Biofinishing of cellulosic fabrics is limited on controlled removal of fibre hairiness, pilling or other non-desired properties after dyeing. Enzymes - at present - are not capable for modifying or chemically cross-linking of cellulose polymers. Some effects on improvements on dimensional stability, however, have been observed. An overview of patents and research on the treatment of cotton with modified or purified cellulases is presented in Table 4.11. The... 

A -Methylol chemistry, utilized for cross-linking of cellulose, has also been successfully exploited as a means for producing durable water repellents. A/ -Methy-lol compounds are prepared by reacting an amine or amide with formaldehyde ... 

Figure 12. Formation of FAS nanocomposite network on the fiber surface (A) and cross-linking of cellulose macromolecules with DMeDHEU in the amorphous regions of fibers (B).

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