Cellulose cyanoethylation

Other substituted celluloses were found to behave similarly to ethyl cellulose. An oxidation susceptibility order was established [23aj allyl cellulose > CMC > benzyl cellulose > ethyl cellulose > cyanoethyl cellulose. The cellulose ethers were found to be less resistant to oxidation than the esters. 

Cellulose acetate Cellulose acetate butyrate Cellulose acetate propionate Cellulose triacetate Ethyl cellulose Cyanoethylated cellulose... 

A major problem in cellulose cyanoethylation is control of the concommitant anionic polymerization of acrylonitrile. At base concentrations greater than 12%, exothermic polymerization occurs rapidly if the temperature is raised to 40 . In the presence of TMAC, the polymerization is suppressed, until a significant increase in the extent of substitution as evidenced by gelation occurs. However, at this point hydroxide ions must be released and a rapid polymerization ensues. Derivatives with apparent M.S. of 6.5 are isolated, but it is difficult to separate homopolyacrylonitrile from cyanoethyl cellulose to confirm if grafting has occurred. However, the initial suppression of base catalysed polymerization is a convincing demonstration of hydroxide transfer and binding in the cellulose phase. 

Cellulose, cyanoethylated Cellulose cyanoethyl ether 9004-41-5 Cellulose, 2-cyanoethyl ether R (CjHsNO) Unk... 

Morita, M., Shigematsu, M. and Sakata, I. (1987). An improvement of the thermoplasticity and the solvent-solubility of cyanoethylated wood by halogen treatment. Cellulose Chemistry and Technology, 21(3), 255-265. 

A, purified cotton cellulose B, cellulose (75%)-polyacrylonitrile (25%) copolymer (y-radiation initiated) C, cyanoethylated cellulose (D.S. 0.7) D, cyanoethylated cellulose (D.S. 0.7) (62%)-polyacrylonitrile (38%) copolymer (y-radiation initiated) E, cellulose (75%)-polyacrylonitrile (25%) copolymer (ceric ion initiated). 

Table V. Elastic Recovery Properties of Fibrous Cyanoethylated Cotton Cellulose (D.S. 0.7) (62%)—Polyacrylonitrile (38%) Copolymer...

The cyanoethylation of polysaccharides has been studied extensively in starch and cellulose. The hydroxyl groups (typically the C-4) on the molecule react with acrylonitrile in the presence of alkali to form a cyanoethyl ester. O-Cyanoethylated cellulose is used in the paper industry to enhance the mechanical strength, heat resistance, and microbiological resistance of the paper. Cyanoethylated starch is used in the textile industry. 

With ionizing radiation (simultaneous steps procedure) with aqueous ZnCU as the solvent for the monomer the fibrous cross section was rounded, and the polymer was concentrated about midway between the inner and outer layers of the fiber (12, 13, 15, 16, 17), as shown in Figure 10A. When cellulose was cyanoethylated before irradiation and aqueous ZnCl2 was the solvent for the monomer, the fibrous cross section was rounded, and a uniform distribution of the polymer was obtained (18, 41), as shown in Figure 10B. 

A Monomer solution 32% acrylonitrile in 80% aqueous ZnCh B Cyanoethylated cellulose (D.S. 0.7) monomer solution same... 

Cellulose reacts with a,/3-unsaturated compounds containing strongly electron-attracting groups to form substituted ethyl ethers. The most common derivative of this type is cyanoethylcellulose. Cyanoethylation requires strongly basic catalysts and is usually carried out in the presence of sodium hydroxide with acrylonitrile as reagent ... 

Highly cyanoethylated celluloses with a DS of about 2.5 are soluble in polar organic solvents. Because of an unusually high dielectric constant and low dissipation factor they can be used as the resin matrix for the phosphorous and electroluminescent lamps. Cyanoethylated kraft wood pulp with a DS of only about 0.2 is used for making insulation paper for transformers. Cyanoethylated paper has also a good thermal and dimensional stability. 

There has been a variety of approaches for imparting antimicrobial activity to cellulosic fibers, many of them developed as part of a weather-resistant finish (Table I). Metal salts, organometallics, resins, sulfur and nitrogen compounds, and chemical modification of hydroxyl groups by acetylation or cyanoethylation are typical methods used to impart antimicrobial activity (125). A survey made in 1966 lists all commercial products available for protecting materials against biodeterioration— trade names, active ingredients, end uses, and names of manufacturers are tabulated (126). 

Vapor or Spraying Applications. Cyanoethylation. Reaction of cellulose with acrylonitrile, CH2=CHCN, a vinyl monomer, was selected for study because it is known to produce several desirable changes in the properties of cellulosic fabrics and yams. After cyanoethylation, undegraded cotton becomes more resistant to microorganism attack, heat, acid, and abrasion (3). Moisture absorption decreases and the electrical properties change. The extent of these changes varies considerably... 

Four types of fabric substrates were cyanoethylated the control, acid hydrolyzed, 50 and 100 Mrad. Fabric specimens 19 X 89 mm were sprayed with a fine mist of 2% NaOH solution using a hand spray bottle until a 100% pickup by weight was achieved. The specimens were then left to air dry until just damp. Six samples were then placed on a rack inside the sealed reaction vessel, which had inlet and outlet connections to permit the acrylonitrile vapor to flow through and around the reactive fabric. This vessel was connected to two bubble bottles containing water and acrylonitrile with which to saturate nitrogen gas as it entered the reaction vessel. The water was necessary to swell the cellulose so the acrylonitrile could penetrate. It was determined that varying nitrogen flow rates and reaction time had little effect on the percent add-on. 

Treatments based on condensation reactions (such as in the classical Williamson synthesis) produce the most stable cotton derivatives. On the other hand, treatments based on addition reactions (such as in the Michael reaction) yield cellulose ethers that are somewhat less stable. This lower level of stability is because of the equilibrium nature of the addition reaction. Typical examples of these two types of cellulose etherification are carboxymethyla-tion [9,329,330] and cyanoethylation [9,329,330,332], respectively, both of which proceed in the presence of alkali. 

Etherification of Wood. Etherification of wood involves the derivatization of hydroxyl groups to other functional groups. In general, etherification of wood produces more stable bonding and generates lower heat of reaction than esterification. Swelling of wood and formation of sodium salt are commonly applied as a pretreatment prior to etherification. Benzylation, cyanoethylation, allylation, and/or hydroxyethylation are commonly used in the etherification of wood. Some methods of etherification of cellulose may also be applied to wood. 

Low-substituted cellulose carbamate301 and partially carboxymethylated or cyanoethylated cotton31,321 also proved highly accessible to grafting with in monomer the presence of an initiator. Grafting onto low-substituted acetate- and allyl cellulose is, however, less efficient because these materials only swell poorly in aqueous solutions or emulsions of the monomer32 331. 

Fig. 30. Plot of (nj/lnj of cellulose ether and ester solutions vs. refractive index of solvent ) 1 2-cyanoethyl-trityl-cellulose, 2 cellulose monophenylacetate, 3 ethyl ceBulose, 4 2-cyanoethyl-acetylcellulose and 5 cellulose benzoate...

Cyanocel [Cytec], TM for chemically modified (cyanoethylated) cellulose. 

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