Chemical functionalization cellulosic fibers

Treatments with Chemicals or Resins. Resin treatments are divided into topical or chemical modifications of the fiber itself. Most chemical treatments of synthetic fibers are topical because of the inert character of the fiber itself and the general resistance of the fiber to penetration by reagents. By contrast, cellulosics and wool possess chemical functionality that makes them reactive with reagents containing groups designed for such purchases. Natural fibers also provide a better substrate for nonreactive topical treatments because they permit better penetration of the reagents. 

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. 

Figure 20 Your body cannot chemically break down the long cellulose fibers in celery, but it needs fiber to function properly.

Sources Reprinted from Cellulose Fibers Bio- and Nano-Polymer Composites, Varshney, V.K., and Naithani, S., Chemical functionalization of cellulose derived from nonconventional sources, Kalia, S., Ed., Springer-Verlag, Berlin, Germany, pp. 43-58. Copyright 2011, with permission from Elsevier Reprinted from Comprehensive Polymer Scierwe, Allen, G. and Bevington, J.C., Eds., Pergamon, Oxford, U.K., pp. 26, 681. Copyright 1986, with permission from Elsevier. 

Varshney, V.K. Naithani, S. Chemical functionalization of cellulose derived from nonconventional sources. In Cellulose Fibers Bio- and Nano-Polymer Composites, Kalia, S., Ed. Springer-Verlag ... 

Cellulosic fibers are characterized by favorable properties such as renewability, biodegradability, environment friendly, excellent affinity for chemical functionalization as well as potential applicability [149]. Cellulosic fibers may be natural, such as cotton, flax, and jute, or regenerated fibers such as lyocell, using NMMO [N-methyl, morpholine-N-oxide] as a solvent for cellulose pulp, viscose, via, more environment-friendly viscose process, as well as bamhoo viscose fibers [24,142,149]. 

Effect of Chemical Functionalization on Functional Properties of Cellulosic Fiber-Reinforced Polymer Composites... 

Two proaches have been reported to immobilize enzyme on ultra-fine cellulose fibers, i.e., adsorption and covalent binding. Both approaches improved the protein binding ability of fiber surfaces by adding chemical functionalities via covalently bonded polymeric chains to ultra-fine cellulose fiber surfaces. Adsorption of enzyme proteins on fiber surfaces was accomplished by ceric ion-initiated graft polymerization of electrolyte acrylic acid monomer and the subsequent enzyme adsorption via secondary forces. 

In addition to conventional vegetal cellulose fibers (Figure 1 A), other forms of cellulose have been assessed in the last few years. The use of micro and nano-cellulose fibers, namely whiskers, obtained from a marine species (Samir, 2005), bacterial cellulose produced by some bacterial strains (Pecoraro, 2008) as well as micro- or nano-fibrillated cellulose prepared by mechanical, enzymatic or chemical treatments of the vegetal fibers (Nakagaito, 2004), for the development of high performance composite materials is attracting researchers from diverse fields (Dufresne, 2008 Lee, 2009), as the addition of very modest amounts of nano fibers leads to new composite materials with superior mechanical properties and new functionalities (Klemm, 2009) when compared with their conventional cellulose fibers counterparts. 

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