Coatings, cellulose ester

Food coatings -cellulose esters m [CELLULOSE ESTERS - ORGANIC ESTERS] (Vol 5)... 

Clostridium welchii, enzymes, effect on blood group substances, IV, 55 Coacervation, I, 277 Coatings, cellulose ester, I, 323 Co-carboxylase, II, 124 Coccidioides immitis, polysaccharide formed by, II, 225 Cocositol, III, 60 Coir, xylan peroentage in, V, 271 Collagenaae, effect on blood group substances, IV, 55... 

Cellulose esters of aromatic acids, aUphatic acids containing more than four carbon atoms and aUphatic diacids are difficult and expensive to prepare because of the poor reactivity of the corresponding anhydrides with cellulose Httle commercial interest has been shown in these esters. Of notable exception, however, is the recent interest in the mixed esters of cellulose succinates, prepared by the sodium acetate catalyzed reaction of cellulose with succinic anhydride. The additional expense incurred in manufacturing succinate esters is compensated by the improved film properties observed in waterborne coatings (5). 

Cellulose esters of unsaturated acids, such as the acetate methacrylate, acetate maleate (34), and propionate crotonate (35), have been prepared. They are made by treating the hydrolyzed acetate or propionate with the corresponding acyl chloride in a pyridine solvent. Cellulose esters of unsaturated acids are cross-linkable by heat or uv light solvent-resistant films and coatings can be prepared from such esters. 

Cellulose esters are considered nontoxic and may be used in food-contact appHcations. However, since cellulose esters normally are not used alone, formulators of coatings and films for use in food packaging should ensure that all ingredients in their formulations are cleared by the United States Food and Dmg Administration for such use. 

Higher butyryl esters, formulated with acryUc polymers, provide coatings with excellent weather resistance, good colorfastness and dispersibiUty, and good flow properties (154). Formulations for a typical automotive refinishing lacquer and a wood furniture lacquer are given in Tables 12 and 13, respectively. Low viscosity, high butyryl cellulose esters tolerate substantial amounts of alcohol solvent without appreciable increase in solution viscosity. 

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). 

An infrequently used method (in pharmaceutical research) for determining the UWL permeability involves measuring transport of molecules across a high-porosity microfilter that is not coated by a lipid. The molecules are able to diffuse freely in the water channels of the microfilter. The filter barrier prevents convective mixing between the donor and acceptor sides, and an UWL forms on each sides of the microfilter. Camenisch et al. [546] measured the effective permeabilities of a series of drug molecules in 96-well microtiter plate-filterplate (Millipore GVHP mixed cellulose ester, 0.22 pm pore) sandwich where the filters were not coated by a lipid. The permeabilities were nearly the same for all the molecules, as shown in Fig. 7.8a. Our analysis of their data, Fig. 7.8b, indicates / aq = 460 pm (sandwich stirred at 150 rpm). We have been able to confirm similar results in our laboratory with different microfilters, using the lipid-free method. 

Plastic pellets, threat from, 20 231 Plastic pumps, for corrosive liquids, 21 76 Plastic refractories, 21 482 Plastics. See also Styrene plastics adhesion of coatings to, 7 91-92 advanced materials, 1 693 cellulose ester applications, 5 404 chemical exposure tests on, 19 583 citric acid application, 6 648 colloidal suspensions, 7 273t colorants for, 7 358-380 development of, 10 168... 

Lacquer. A coating comprised of resins such as cellulose esters or ethers, shellac or gum, or allethyl alcohol that evaporates easily. The application process involves no chemical change, only the evaporation of the solvent leaving behind a hard, durable finish. 

Uses Solvent for paints, tin coatings, agricultural chemicals, and synthetic resins excellent solvent for vinyl resins, cellulose esters, and ethers pesticides storing lacquers pesticide manufacturing intermediate in the manufacture of 3,5-xylenol, 2,3,5-trimethylcyclohexanol, and 3,5-dimethylaniline. 

The most important cellulose ester is cellulose acetate because of its use in fibers and plastics. They were first made in 1865 by heating cotton with acetic anhydride. During World War I, cellulose acetate replaced the highly flammable CN coating on airplane wings and fuselage fabrics. 

Acrylic -polycarbonate blends [POLYCARBONATES] (Vol 19) - [FIBERS-ACRYLIC](Vol 10) - [FIBERS - CELLULOSE ESTERS] (Vol 10) - [COATINGS] (Vol 6) - [FIBERS-REGENERATEDCELLULOSICS](Vol 10) -m friction materials [BRAKE LININGS AND CLUTCH FACINGS] (Vol 4)... 

Cellulose esters of the 2-.. 3-. and 4-carbon acids are readily prepared by the cellulose-anhydride reaction the acetate ester and the mixed acetate butyrate and acetate propionate esters arc manufactured and used in large amounts. Esters of higher acids require different synthesis techniques and tend to be prohibitively expensive except as specialty products. Some arc in commercial production, however. Cellulose acclalc phlhalatc, for example, is manufactured for use as an enteric coating on pills. 

The organic cellulose ester plastics are versatile materials and can be processed by almost any hot-processing technique used for thermoplastics. The principal techniques for all three plastics are injection molding and extrusion. Blow molding is also possible. Butyrate and propionate powder are used in tluidized-bed and electrostatic coating processes, as well as in the rotational molding process. 

Coumarone-indene resins are sold under various trade names Cumar, Neville, Nevindene, Paradene Picoumaron. Numerous applications in industry include uses in plastics, protective coatings, adhesives, lacquers, and as plasticizers for cellulose esters vinyl resins Refs i) Beil 17, 56 [ 57.1 2) Kirk Othmer... 

With the exception of the blue copper phthalocyanine derivatives, these products are azo dyes that are soluble in polar solvents such as alcohols, glycols, esters, glycol ethers, and ketones. Dyes soluble in alcohols and esters are used in protective lacquers for the transparent coating of metal (aluminum) foils and other materials, such as wood (greening lacquers) in flexographic inks for the printing of metal foils, cellophane, and paper as well as for the coloration of cellulose esters, celluloid, and poly(vinyl acetates), and, in the office supplies sector, for... 

Digitoxin potentially adsorbs onto glass, plastic, and inline intravenous filters containing cellulose ester membranes, some aqueous solutions such as 5% glucose, or 0.9% sodium chloride. The loss in potency may be minimized by pretreatment of the filter with a polymer coating. Such losses in potency were not found with 30% alcohol solutions.103104... 

Cellulose ethers are a wide-ranging family of cellulose derivatives, commonly used in the food and pharmaceutical industry. Methyl, ethyl and propyl cellulose esters are used as drilling aids in mining and as detergents. They are also used as coatings and adhesives in cosmetic and pharmaceutical products. 

Starch esters are thermoplastic materials with properties that are somewhat similar to that of cellulose esters. In particular, starch acetate (DS < 0.2) is used as a coating agent for paper and as a food or detergent additive. 

Leather, cellulose ester coatings for, I, 324 Leather industry, lactic acid in, IV, 318... 

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