Cellulose, acetate, butyrate and propionate

The silicone oils may be non-reactive, or of the reactive or curing type which depends on their purpose. The reactive or curing-t3 e silicones include combinations of alcohol-modified silicone oils and isocyanates. In addition, those silicone 

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The cellulose nitrate plastics were adaptable, easy to work, and quite durable, but had the disadvantages of being plasticized with camphor and flammability (they burnt, in fact, quite violently). At one time the smell of camphor was thought pleasant (even therapeutic) but instances have been cited of harm to children attributed to inhaling this vapour. So, while the acetates were not quite so attractive in terms of ease of fabrication it was inevitable eventually that the so-called safety plastic would supersede its forerunner. Among other uses it was stitched into motor car tonneau covers as flexible glazing, and thicker transparent sheet was cut and formed into cockpit canopies for aircraft [though by that time the material preferred for this purpose was poly(methyl methacrylate)]. Later on, in their turn, sheets made from cellulose acetate butyrate and propionate took over some of the uses of earlier commercial materials. 

Cellidor. [Albis UK Ltd.] Cellulose acetate butyrates and propionates thermoplastic for automotive, tool, building, furniture industries, domestic appliances, lighting, elec., radio and TV industries, optical, photographic, stationery, toy, toiletries, and pkg. plics. 

Other cellulosics, cellulose acetate butyrate and propionate are cemented in accordance with the technique described for cellulose acetate. In the case of dope cements, the plastic to be dissolved in solvents is cellulose propionate. Similarly for ethyl cellulose plastic, the strongest bonds are made by solvents or by solvents bodied with ethyl cellulose plastic. 

The cellulose esters with the largest commercial consumption are cellulose acetate, including cellulose triacetate, cellulose acetate butyrate, and cellulose acetate propionate. Cellulose acetate is used in textile fibers, plastics, film, sheeting, and lacquers. The cellulose acetate used for photographic film base is almost exclusively triacetate some triacetate is also used for textile fibers because of its crystalline and heat-setting characteristics. The critical properties of cellulose acetate as related to appHcation are given in Table 10. 

The most important of the esters is cellulose acetate. This material has been extensively used in the manufacture of films, moulding and extrusion compounds, fibres and lacquers. As with all the other cellulose polymers it has, however, become of small importance to the plastics industry compared with the polyolefins, PVC and polystyrene. In spite of their higher cost cellulose acetate-butyrate and cellulose propionate appear to have retained their smaller market because of their excellent appearance and toughness. 

Cellulose Acetate Butyrate and Cellulose Acetate Propionate... 

Since the cellulose esters CA. CAB, and CP are chemical raw materials, the won plastic was used in the preceding paragraph to differentiate the product from the raw material. The cellulose ester plastics are commonly called simply "acetate. butyrate." and "propionate." and these names will be used in the text that follows. 

Used as low-temperature-resistant and low-viscosity plasticizer for PVC and its copolymers and cellulose esters, e.g., cellulose acetate butyrate, and cellulose propionates. May be found in eyeglass frames, safety goggles, animal collars, decorative trims and various types of film. 

Cellulose acetate and mixed ester (include acetate butyrate and propionate plastics)... 

FIGURE 2.2 Structures of cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate. 

TENITE esters are cellulose derivatives of acetate, butyrate, and propionate. Tenite plastics for molding and extrusion are supplied in the form of pellets. These thermoplastic resins have good processability and finished articles may be resoftened by heat and reshaped by the application of suitable forces. 

Cellulosics comprise of a class of polymers which include cellulose nitrate, three organic esters, namely, cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate and one ether, namely, ethyl cellulose. Cellulose acetate film or cellophane finds application in the packaging. industry. Cellulose acetate butyrate is the material used between sheets of glass when making safety glass for the automotive industry. Xanthanated cellulose or rayon is used for making fabrics. 

The earliest thermoplastics were the cellulosics. Celluloid or cellulose nitrate, followed by cellulose acetate, cellulose acetate butyrate and, more recently, cellulose propionate, have all found their special uses, but cellulose nitrate is used very little currently because of flammability risks. 

From 1946 to mid-1987, Farbenfabriken Bayer AG in Germany was the European producer of cellulose acetate, cellulose acetate butyrate (CAB), and cellulose acetate propionate (CAP) before closing its faciUties. Bayer s exit from the cellulose acetate mixed esters business leaves Eastman Chemical Co. in the United States as the sole producer of CAB/CAP resins. 

Mixed esters such as cellulose acetate sulfate [51910-28-2] (21,22), cellulose acetate butyrate sulfate [57485-48-0] (21,22), cellulose acetate propionate sulfate [67351-39-7] (23), and ethylceUulose sulfate (24) are described in the patent Hterature but are not of commercial importance. 

Acrylic and modified acrylic Cellulosics acetate Butyrate Propionate... 

Cellulosic They are tough, transparent, hard or flexible natural polymers made from plant cellulose feedstock. With exposure to light, heat, weather and aging, they tend to dry out, deform, embrittle and lose gloss. Molding applications include tool handles, control knobs, eyeglass frames. Extrusion uses include blister packaging, toys, holiday decorations, etc. Cellulosic types, each with their specialty properties, include cellulose acetates (CAs), cellulose acetate butyrates (CABs), cellulose nitrates (CNs), cellulose propionate (CAPs), and ethyl celluloses (EC). 

Systematic investigations were carried out for the preparation of cellulose acetate of D.S. 2,65 and other mixed esters which included cellulose acetate-propionate, cellulose acetate-butyrate, cellulose acetate-benzoate and cellulose acetate-methacrylate. The experimental conditions were optimised for maximum yield of the ester. Flat osmotic membranes were developed from these esters and characterised for their osmotic and transport properties. The nmmbra-nes were evaluated in a reverse osmosis laboratory test-cell using 5OOO ppm sodium chloride solution at 40 bars pressure. Table 1 presents the typical performance data of these membranes. 

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. 

These two cellulose esters are somewhat similar in properties and applications. Cellulose acetate butyrate is commonly referred to in the chemical industry as CAB. while cellulose acetate propionate is simply termed cellulose propionate" and referred to as CAP or as CP. 

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