Carboxymethylated cellulose fibers

Cellulosic fibers such as cotton and viscose rayon can be treated with chloroacetic acid to make highly absorbent carboxymethyl cellulose fibers. When partially car-boxymethylated, the carboxylic acid groups in the fibers are able to absorb a large amount of water into the fiber structure, hence the treated fibers are capable of a high degree of swelling when wet in water. 

The addition of carboxymethyl cellulose (CMC) and methyl cellulose (MC) to the nutrient solution (0.5-2.0 m/v %) effects a change of the fiber and network architecture [38] (Fig. 7). In the first case, the crystallization of the BC is affected by agglomeration of the CMC onto the fibers during self-assembly. The additive seems to compete with the BC for hydrogen-binding sites during ribbon construction [39] (Fig. 7a). In the second case, the adsorption takes place mainly on the planar ribbons (Fig. 7c). 

The carboxymethyl cellulose (CMC) derivatives and carboxymethyl starch (CMS) are effective antiredeposition agents that are cellulose-containing fibers such as cotton and blends of cotton and synthetic fibers. However, CMC has virtually no effect on pure synthetic fibers. Other effective antiredeposition agents and soil repellents have been developed (Fig. 5.4) [20]. 

Carboxymethylated celluloses. These were prepared by the reaction of celluloses with monochloroacetic acid, followed by crosslinking. These are mostly used in fiber form. 

Suzawa, T. and Shirahama, H., Studies of surface adsorbability of sodium carboxymethyl cellulose onto nylon 6 fiber by potential method. Colloid Polym. Sci., 257, 732, 1979. 

Carrot fiber, prepared as an alcohol-acetone insoluble residue of cell wall material, binds deoxycholate and chenodeoxycholate under physiological conditions with the release of protons. Removal of calcium pectate from this material by extraction with ammonium oxalate reduces the capacity of carrot fiber to bind bile acids. Calcium carboxymethyl cellulose exhibits similar binding activity, whereas free carboxymethyl cellulose shows no binding. Calcium pectate prepared from citrus pectin and dissolved in water was found to bind bile acids under conditions used with carrot fiber. These results suggest that binding occurs through formation of salt linkage between calcium pectate in the cell wall residue and a bile acid. 

The Ci, Cx concept has recently been extensively studied by a number of workers (16,23, 24, 27, 31, 32,46), for two species of Trichoderma, namely T. viride and T. koningi. It was shown that cell-free culture solutions of these fungi were able to solubilize cotton fibers. The solubilization of cotton fibers is also a way of measuring the activity of the Ci enzyme. In the most recent of these publications (46) Selby and Maitland were able to isolate the Ci enzyme from culture filtrates of T. viride. The enzyme was shown not to act upon cellobiose or carboxymethyl cellulose and to lose its ability to solubilize cotton in the absence of the Cx component. The mechanism of action of the Ci enzyme is thus still obscure although many different hypotheses have been presented (34). 

It is well known that it is difficult to achieve miscibility of two polymers. However, it is often possible to obtain apparently stable solutions in which two polymers are dissolved without phase separation. Examples of water-soluble polymers that were mixed with PVA and spun by wetspinning are polyacrylic acid, sodium carboxymethyl cellulose, various proteins, and polyvinyl aminoacetals. The most common objective of mixed-spinning was the modification of dyeing properties, but this method is also applied to modify many other properties of PVA fiber. 

Infrared spectroscopy is a useful tool to identify functional groups through vibrational frequencies in polymers to evaluate changes in structure This research was focused in graft copolymerization of Hydroxyethyl methacrylate (HEMA) onto chicken feathers fibers (CFF) and carboxymethyl cellulose (CMC), evaluating effect of reaction conditions (time reaction, monomer concentration, initiator concentrations) on grafting yield and probe presence of HEMA in copolymers by means Infrared Spectroscopy (IR). 

It is necessary to swell the cellulose fibers prior to treatment with sodium chloroacetate this is done with aqueous caustic. Sodium chloroacetate reacts with the hydroxyl groups on cellulose, of which theoretically there are three per glucose monosaccharide. The reaction is usually run in aqueous organic diluent in which both the cellulose and the carboxymethylcellulose are swellable, but insoluble. The term degree of substitution (DS) describes the average number of carboxymethyl groups attached to each glucose monosaccharide. 

Sodium carboxymethyl cellulose Soapy water Selective precipitation onto clothing fibers Prevents oils from redepositing on clothing during detergent washing antiredeposition agent... 

Fibers bonded with water-soluble polymers such as starches, carboxymethyl cellulose, polyethylene oxides, polyvinyl alcohols, polyacrylates, etc. This may involve bonding of biodegradable fibers or films or other structures that will break down in the flush. 

Figure 6 Percent levels of dicarbonyls in dialdehyde cotton gauze (DAG I and II) and carboxylates (CMC III and TV) on carboxymethylated cellulose as determined by titration on modified cotton fibers. Data are mean SE of triplicate determinations.

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