Cellulosics solvents for

Henniges U, Schiehser S, Rosenau T, Potthast A (2009) Cellulose solubility dissolution and analysis of problematic cellulose pulps in the solvent system DMAc/LiCl. In Liebert TF, Heinze TJ, Edgar KJ (eds) Cellulose solvents for analysis, shaping and chemical modification. ACS symposium series, vol 1033. American Chemical Society, Washington, pp 165-177... 

Diacetin is chiefly the 1 3-diacelate CH3OOCCH3.CHOH.CH2OOCCH3. Used as plasticizer for cellulose acetate lacquers and as a solvent for basic dyes. 

CH2CI2. A colourless liquid with a chloroform-like odour b.p. 4I°C. Prepared by heating chloroform with zinc, alcohol and hydrochloric acid manufactured by the direct chlorination of methane. Decomposed by water at 200°C to give methanoic and hydrochloric acids. Largely used as a solvent for polar and non-polar substances, particularly for paint removal (30%), dissolving cellulose acetate and degreasing (10%). It is more stable than carbon tetrachloride or chloroform especially towards moisture or alkali. It is somewhat toxic. U.S. production 1981 280000 tonnes. 

CH3CH(0H)C(0)0Et. A colourless liquid with a pleasant odour, b.p. 154 C. Manufactured by distilling a mixture of ( )-lactic acid, ethanol and benzene in the presence of a little sulphuric or benzenesulphonic acid. It is a solvent for cellulose nitrate and acetate and also for various resins. Used as a lacquer solvent. 

Glycerol ct-dichlorohydrin, sym-dichloroiso-propyl alcohol, 1,3-dichloro-2-hydroxypropane, CH2CI-CHOH-CH2C1. Colourless liquid with an ethereal odour b.p. 174-175" C. Prepared by passing dry HCl into glycerin containing 2% elhanoic acid at 100-1 lO C. Converted to x-epichlorohydrin by K.OH, Used as a solvent for cellulose nitrate and resins. 

CH3COCH2CH1COCH3. Colourless liquid which becomes yellow on standing b.p. I9PC. Obtained by boiling 2,5-dimethylfuran with dilute sulphuric acid. It readily condenses with a variety of substances to give derivatives of furan, thiophen and pyrrole, and is a solvent for cellulose acetate. 

C5H10O2, CHjCOOPr. Colourless liquid with a fragrant odour b.p. 88 C. Manufactured by leading propene into hot ethanoic acid containing sulphuric acid, or by heating isopropyl alcohol with ethanoic and sulphuric acids. Used as a solvent for cellulose nitrate and various gums. 

McjC = CHCOCH3. Colourless liquid b.p. 129"C, with a strong peppermint-like odour. Prepared by distilling diacetone alcohol in the presence of a trace of iodine. Converted to phorone by heating in propanone with dehydrating agents such as sulphuric acid. It is a solvent For cellulose acetate and ethyl-cellulose and other polymers. 

Me2C = CHCOCH= CMca- Yellow liquid having a camphor-like odour m.p. 28 C, b.p. 198-5°C. It is formed when propanone is saturated with HCl and allowed to stand. Resembles camphor in many of its properties and is a solvent for cellulose nitrate. Used to prepare diisobutyl ketone (reduction). 

Schweizer s reagent The dark blue solution obtained by dissolving Cu(OH)2 in concentrated ammonia solution. Used as a solvent for cellulose, the cellulose is precipitated on acidification. Used in the cuprammonium process for the manufacture of rayon. 

Carbon disulphide is an excellent solvent for fats, oils, rubber, sulphur, bromine and iodine, and is used industrially as a solvent for extraction. It is also used in the production of viscose silk, when added to wood cellulose impregnated with sodium hydroxide solution, a viscous solution of cellulose xanthate is formed, and this can be extruded through a fine nozzle into acid, which decomposes the xanthate to give a glossy thread of cellulose. 

The Courtaulds Tencel Process. The increasing costs of reducing the environmental impact of the viscose process coupled with the increasing likelihood that the newer cellulose solvents would be capable of yielding a commercially viable fiber process led Courtaulds Research to embark on a systematic search for a new fiber process in the late 1970s. 

Tables 1 and 2 Hst the important physical properties of formamide. Form amide is more highly hydrogen bonded than water at temperatures below 80°C but the degree of molecular association decreases rapidly with increa sing temperature. Because of its high dielectric constant, formamide is an excellent ionizing solvent for many inorganic salts and also for peptides, proteias (eg, keratin), polysaccharides (eg, cellulose [9004-34-6] starch [9005-25-8]) and resias.

Almost all of the cyclohexane that is produced in concentrated form is used as a raw material in the first step of nylon-6 and nylon-6,6 manufacture. Cyclohexane also is an excellent solvent for cellulose ethers, resins, waxes (qv), fats, oils, bitumen, and mbber (see Cellulose ethers Resins, natural Fats AND FATTY OILS Rubber, NATURAL). When used as a solvent, it usually is in admixture with other hydrocarbons. However, a small amount is used as a reaction diluent in polymer processes. 

Uses. Diacetone alcohol is a widely used solvent in the coatings industry where it finds appHcation in hot lacquers which require high boiling components, and in bmshing lacquers where its mild odor, blush resistance, and flow-out properties are desired. Diacetone alcohol is also a solvent for nitrocellulose, cellulose acetate, and epoxy resins. 

Other. 2-Nitro-1-butanol is an excellent solvent for many polyamide resins, cellulose acetate butyrate, and ethylceUulose. It can be utilized in paint removers for epoxy-based coatings. 2-Hydroxymethyl-2-nitro-l,3-propanediol is usebil for control of odors in chemical toilets. Its slow release of formaldehyde ensures prolonged action to control odor, and there is no reodorant problem which sometimes is associated with the use of free formaldehyde. 2-Hydroxymethyl-2-nitro-l,3-propanediol solutions are effective preservative and embalming fluids. The slow Uberation of formaldehyde permits thorough penetration of the tissues before hardening. 

Pentachloroethane is a good solvent for cellulose acetate, certain cellulose ethers, and for natural gums and resins, but its high toxicity has discouraged these uses. Pentachloroethane is still used as an intermediate in some tetrachloroethylene processes. 

One principal use of cyclohexanol has been in the manufacture of esters for use as plasticizers (qv), ie, cyclohexyl and dicyclohexyl phthalates. In the finishes industry, cyclohexanol is used as a solvent for lacquers, shellacs, and varnishes. Its low volatiUty helps to improve secondary flow and to prevent blushing. It also improves the miscibility of cellulose nitrate and resin solutions and helps maintain homogeneity during drying of lacquers. Reaction of cyclohexanol with ammonia produces cyclohexylamine [108-91-8], a corrosion inhibitor. Cyclohexanol is used as a stabilizer and homogenizer for soaps and synthetic detergent emulsions. It is used also by the textile industry as a dye solvent and kier-boiling assistant (see Dye carriers). 

The acetates of most alcohols are also commercially available and have diverse uses. Because of their high solvent power, ethyl, isopropyl, butyl, isobutyl, amyl, and isoamyl acetates are used in ceUulose nitrate and other lacquer-type coatings (see Cellulose, esters). Butyl and hexyl acetates are exceUent solvents for polyurethane coating systems (see Coatings Urethane polymers). Ethyl, isobutyl, amyl, and isoamyl acetates are frequentiy used as components in flavoring (see Flavors and spices), and isopropyl, benzyl, octyl, geranyl, linalyl, and methyl acetates are important additives in perfumes (qv). 

Because of these influences cellulose acetate can be dissolved in a variety of media, although a liquid suitable as a solvent for cellulose acetate with a degree of substitution of two would be unlikely to be a solvent for acetates with degrees of substitution of either one or three. 

Methylene chloride has a wide variety of markets. One major use is a paint remover. It is also used as a degreasing solvent, a blowing agent for polyurethane foams, and a solvent for cellulose acetate. 

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