Films cellulose acetate

The principal chemical iadustry based on wood is pulp and paper. In 1995, 114.5 x 10 metric tons of wood were converted iato - 60 x 10 metric tons of fiber products ranging from newsptint to pure cellulose ia the United States (1,76). Pure cellulose is the raw material for a number of products, eg, rayon, cellulose acetate film base, cellulose nitrate explosives, cellophane, celluloid, carboxymethylceUulose, and chemically modified ceUulosic material. 

Large quantities of secondary cellulose acetate are used worldwide in the manufacture of filter material for cigarettes. Because of its excellent clarity and ease of processing, cellulose acetate film is widely used in display packaging and extmded plastic film for decorative signs (see Packaging materials). Injection-molded plastics of cellulose acetate are used in toothbmsh handles, computer bmshes, and a large variety of other appHcations (7). 

Low viscosity cellulose acetate is used in lacquers and protective coatings for paper, metal, glass, and other substrates and as an adhesive for cellulose photographic film because of its quick bonding rate and excellent bond peel strength (135) (see Coatings). Heat-sensitive adhesives for textiles have also been prepared from cellulose acetate (136). Extmded cellulose acetate film makes an excellent base for transparent pressure-sensitive tape (137) (see Adhesives). 

Cellulose acetate films, specially cast to have a dense surface and a porous substmcture, are used in reverse osmosis to purify brackish water (138—141) in hollow fibers for purification of blood (artificial kidney) (142), and for purifying fmit juices (143,144) (see Membrane technology). 

Weathering in a tropical climate causes polyethylene containers to crack, polypropylene (PP) ropes to rupture, and ABS telephones to foil. Polystyrene (PS) and cellulose acetate films used as packing materials also fail due to weathering. 

UV absorbers have been found to be quite effective for stabilization of polymers and are very much in demand. They function by the absorption and harmless dissipation of the sunlight or UV-rich artificial radiation, which would have otherwise initiated degradation of a polymer material. Meyer and Geurhart reported, for the first time in 1945 [10], the use of UV absorber in a polymer. They found that the outdoor life of cellulose acetate film was greatly prolonged by adding phenyl salicylate (salol) [10]. After that, resorcinol monobenzoate, a much more effective absorber, was introduced in 1951 [11] for stabilization of PP, but salol continued to be the only important commercial stabilizer for several years. The 2,4-dihydroxybenzophenone was marketed in 1953, followed shortly by 2-hydroxy-4-methoxybenzophenone and other derivatives. Of the more commonly known UV absorbers, the 2-hydroxybenzophenones, 2-hy-droxy-phenyl-triazines, derivatives of phenol salicylates, its metal chelates, and hindered amine light stabilizers (HALS) are widely used in the polymer industry. 

A commercially available cellulose acetate film which we would now describe as homogeneous or isotropic, gave the results shown in Row 2 of Table I. The volumetric permeation rate of water per unit membrane area, called the water permeation flux Jl mVm day, and the water permeation constant. A, m m day atm were both very low, but a salt rejection of 94 percent was obtained. We define ... 

Note Data for cellulose acetate (film thickness = 0.088 mm) is taken from (a) Reference 27 (b) Reference 8, p. 136. 

While other organic esters are commercially available, namely cellulose butyrate and cellulose propionate, by far the most widely used is cellulose acetate, which is available as plastics, in films, sheets, fibers, and lacquers. Cellulose acetate is used in the manufacture of display packaging and as extruded film for decorative signs, and to coat a variety of fibers. Injected molded products include toothbrush handles, combs, and brushes. It is also used in lacquers and protective coatings for metal, glass, and paper. Cellulose acetate films are used in reverse osmosis to purify blood, fruit juices, and brackish water. Some eyeglass frames are... 

Kodacel Cellulose acetate film Eastman Chemical... 

Several variants of the biosensor in Scheme 5 have been proposed. One is a CPE containing at its tip a paste of graphite powder loaded with HRP and ferrocene ([Cp Fe(II) Cp]) mediator, which is further covered with a cellulose acetate film coated with Nafion. The biosensor is mounted on a FIA system in a three-electrode setup, as working electrode at a potential of 4-100 mV vs. SCSE and a Pt counterelectrode. The LOD (SNR 6) for H2O2 is 200 fmol (20 p,L injection of 10 nM solution), with linearity up to 25 In... 

Decraene, V., Pratten, J., and Wilson, M. (2006). Cellulose acetate films containing Toluidine Blue and Rose Bengal is an effective antimicrobial coating when exposed to white light. Appl. Environ. Microbiol. 72(6), 4436 439. 

This so-called "active" layer has characteristics similar to those of cellulose acetate films but with a thickness of the order of 0.1 micrometer (jjm) or less, whereas the total membrane thickness may range from approximately 75 to 125 ym (see Figure 1). The major portion of the membrane is an open-pore sponge-like support structure through which the gases flow without restriction. The permeability and selectivity characteristics of these asymmetric membranes are functions of casting solution composition, film casting conditions and post-treatment, and are relatively independent of total membrane thickness. 

Desalination capability of cellulose acetate film demonstrated Breton and Reid -1959... 

Figure 8.6 The difference between selectivities calculated from pure gas measurements and selectivities measured with gas mixtures can be large. Data of Lee et al. [13] for carbon dioxide/methane with cellulose acetate films. Reprinted from S.Y. Lee, B.S. Minhas and M.D. Donohue, Effect of Gas Composition and Pressure on Permeation through Cellulose Acetate Membranes, in New Membrane Materials and Processes for Separation, K.K. Sirkar and D.R. Lloyd (eds), AIChE Symposium Series Number 261, Vol. 84, p. 93 (1988). Reproduced with permission of the American Institute of Chemical Engineers. Copyright 1988 AIChE. All rights reserved...

Figure 1. Kinetic parameters for grafting of styrene onto pre-irradiated cellulose acetate films at 50°C from a styrene/MeOH (1/1) solution. Key GR, average growth rate of graft radical PR, average termination probability DA, initiation rate of grafting. (Adapted from Figure 6 of Ref. 2.)...

Cellulose acetate film can be welded in this way, subject to constraints similar to those for rigid poly(vinyl chloride) film. 

Figure 7. Brillouin spectrum of a commercial cellulose-acetate film...

Wilson, W. K., Forshee, B. W., Degradation of Cellulose Acetate Films, ... 

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