Cellulosics cellulose propionate

Cellulose monoacetate. See Cellulose acetate Cellulose nitrate. See Nitrocellulose Cellulose, polyanionic. See Carboxymethylcellulose sodium Cellulose powder Cellulose, powdered. See Cellulose Cellulose propionate. See Cellulose acetate propionate Cellulose pulp. See Cellulose... 

Other mixed esters, eg, cellulose acetate valerate [55962-79-3] cellulose propionate valerate [67351-41-17, and cellulose butyrate valerate [53568-56-2] have been prepared by the conventional anhydride sulfuric acid methods (25). Cellulose acetate isobutyrate [67351-38-6] (44) and cellulose propionate isobutyrate [67351-40-0] (45) have been prepared with a 2inc chloride catalyst. Large amounts of catalyst and anhydride are required to provide a soluble product, and special methods of delayed anhydride addition are necessary to produce mixed esters containing the acetate moiety. Mixtures of sulfuric acid and perchloric acid are claimed to be effective catalysts for the preparation of cellulose acetate propionate in dichi oromethane solution at relatively low temperatures (46) however, such acid mixtures are considered too corrosive for large-scale productions. 

Low viscosity cellulose propionate butyrate esters containing 3—5% butyryl, 40—50% propionyl, and 2—3% hydroxyl groups have excellent compatibihty with oil-modified alkyd resins (qv) and are used in wood furniture coatings (155). Acetate butyrate esters have been used in such varied apphcations as hot-melt adhesive formulations (156), electrostatically spray-coated powders for fusible, non-cratering coatings on metal surfaces (157—159), contact lenses (qv) with improved oxygen permeabiUty and excellent wear characteristics (160—162), and as reverse-osmosis membranes for desalination of water (163). 

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 nitrate Cellulose acetate Cellulose accetate- hutyrate Cellulose acetate- propionate Cellulose propionate Ethyl cellulose... 

In the mid-1950s cellulose propionate became commercially available (Forticel-Celanese). This material is very similar in both cost and properties to CAB. Like CAB it may take on an excellent finish, provided a suitable mould is used, it is less hygroscopic than cellulose acetate, and is easily moulded. 

Cellulose acetate-propionate (Tenite Propionate-Kodak) is similar to cellulose propionate. With the shorter side chains, cellulose propionate and cellulose acetate propionate tend to be harder, stiffer and of higher tensile strength than CAB. Like CAB they are easy to vacuum form and also tend to be used for similar applications such as steering wheels, tool handles, safety goggles and blister packs. 

Cellulose Propionate H All conventional processes Toys, pens, aitomo-tive parts, radio cases, toothbrushes, handles... 

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). 

Cellulose acetate Cellulose propionate Cellulose acetate butyrate High-density polyethylene Nylon... 

The same procedure has been employed to increase the hydrophobic character of cellulose, by introducing fluorine-containing groups, e.g., 2,2-difluoroethoxy 2,2,2-trifluoroethoxy and octafluoropentoxy. Incorporation of hydrophobic moieties into cellulose is expected to increase the polymer compatibility with other materials, e.g., synthetic polymers. Note that an important part of incompatibility is due to the highly hydrophilic character of cellulose. Decreasing this character is expected to affect Tg of the derivative, as shown by cellulose propionate/octafluoropentoxy acetate (total DS = 3.0, partial DS in each moiety = 1.5), whose Tg is only 53 °C. The products are more stable than their fluorine-free counterparts, and the terminal CF2 - H group affects Tg much less than OH-substituted trifluoroethoxy celMose derivatives [196,197]. 

The exceptional ability of PCL to form blends with many other polymers has stimulated a large amount of research. The subject has been reviewed a number of times (7,8). To date, the potential of such blends for drug delivery has been largely unexploited. The permeability of blends of PCL with cellulose propionate, cellulose... 

Chloropromazine (8—34 wt% loading) has been microencapsulated in PCL-cellulose propionate blends by the emulsion solvent evaporation method (61). Phase separation for some ratios of the two polymers was detectable by SEM. The release rate from microcapsules in the size range of 180-250 pm in vitro (Fig. 11) was directly proportional to the PCL content of the blend, the half-life (50% drug release)... 

Chang, R. K., Price, J. C., and Whitworth, C. W., Control of drug release rates through the use of mixtures of poly-caprolactone and cellulose propionate polymers, Pharm. Technol. 10, 24, 26, 29, 32-33, 1986. 

Cellulose phosphate(s), 5 401 8 29 20 459 flame resistant, 8 27 paper, 5 408 solubility of, 5 402 Cellulose propionate manufacture of, 5 418 moisture properties, 5 416t Cellulose propionate valerate, 5 421 Cellulose propionate isobutyrate, 5 421 Cellulose substrates, dyeability of, 9 482-483... 

Random copolymerization of one or more additional monomers into the backbone of PET is a traditional approach to reducing crystallinity slightly (to increase dye uptake in textile fibers) or even to render the copolymer completely amorphous under normal processing and use conditions (to compete with polycarbonate, cellulose propionate and acrylics in clear, injection molded or extruded objects). 

Komarek, R.J., Gardner, R.M., Buchanan, C.M. and Gedon, S. (1993). Biodegradation of radiolabelled cellulose acetate and cellulose propionate. Journal of Applied Polymer Science, 50(10), 1739-1746. 

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