Acetate film backing

Ethylene vinyl acetate is mainly used in topical pharmaceutical applications as a membrane or film backing. Generally it is regarded as a relatively nontoxic and nonirritant excipient. 

Poly(vinyl acetate) emulsions are used to prime-coat fabrics to improve the adhesion of subsequent coatings or to make them adhere better to plastic film. Plasticized emulsions are appHed, generally by roUer-coating, to the backs of finished mgs and carpets to bind the tufts in place and to impart stiffness and hand. For upholstery fabrics woven from colored yams, PVAc emulsions may be used to bind the tufts of pile fabrics or to prevent sHppage of synthetic yams. 

Hydrocortisone microspheres (108,109) and films (110) based on poly(lactic acid) have been investigated. A cage implant technique was used to study the performance of monolithic poly (DL-lactide) films loaded with hydrocortisone acetate (110). Films 1.5 x 0.6 cm were inserted into titanium wire-mesh cages 3.5 x 1.0 cm. The cages were implanted in the backs of rats and the inflammatory exudate was sampled periodically. The white cell concentration in the samples was lower than that of controls at all times during the 21-day test. 

Two different RO membrane types were evaluated in this study. The first was a standard cellulose acetate based asymmetric membrane. The second type, a proprietary cross-linked polyamine thin-film composite membrane supported on polysulfone backing, was selected to represent potentially improved (especially for organic rejection) membranes. Manufacturer specifications for these membranes are provided in Table III. Important considerations in the selection of both membranes were commercial availability, high rejection (sodium chloride), and purported tolerance for levels of chlorine typically found in drinking water supplies. Other membrane types having excellent potential for organic recovery were not evaluated either because they were not commercially... 

Figure 28-11 Schematic representation of the layer structure of color film and the color changes that occur on development. The actual film also contains a filter below the blue-sensitive layer to remove the blue light passing through this layer (because all emulsions are sensitive to blue), an antihalation layer below the red to prevent scattering of the light back through the emulsion, and a film base, such as cellulose acetate or poly-1,2-ethanediyl 1,4-benzenedioate, to support the emulsion.

Suitable for a wide variety of nonwoven end-use applications. SUNCRYL CP-75 is also used as a back coating binder for stabilizing corduroy woven fabrics. SUNCRYL CP-75 is a soft, selfcrosslinking vinyl acetate-acrylic copolymer emulsion which forms a soft, flexible film. 

Plasticizer and adhesion promoter for polyvinyl acetate and other film-formers. Component in latex adhesives, paints, emulsion waxes, polishes, carpet backing, and variety of other formulations. 

The backing material and release liner can be fabricated from a variety of materials including polyvinylchloride, polyethylene, polypropylene, ethylene-vinyl acetate and aluminium foil. The most important property of these materials is that they are impervious to both drug and formulation excipients. The most useful backing materials conform with the skin and provide a balanced resistance to transepidermal water loss, which will allow some hydration of the stratum corneum, yet maintain a healthy subpatch environment. The release liners are usually films or coated papers and must separate easily from the adhesive layer without lifting off any of the pressure-sensitive adhesive. Silicone release coatings are used with acrylate and rubber-based adhesive systems, and fluorocarbon coatings with silicone adhesives. 

Figure 6.18. (A) UV-Vis spectrum of a ZnTRP film on Pt and (B) corresponding photoaction spectrum spectrum at 0.22 V (C) photoaction spectra of an electrostatic assembled ZnTRP/TPPS film on ITO as a function of the thickness and illumination (front or back). Electrolyte O2 saturated LiCF3S03 aqueous acetate buffer (pH = 4.7) solution.

The chemical industry s interest in polymers dates back to the 19th century. In those days it was a case of synthetically modifying natural polymers with chemical reagents to either improve their properties or produce new materials with desirable characteristics. Notable examples were nitration of cellulose giving the explosive nitrocellulose, production of regenerated cellulose (rayon or artificial silk) via its xanthate derivative, and vulcanization of rubber by heating with sulphur. Manufacture of acetylated cellulose (cellulose acetate or acetate rayon) developed rapidly from 1914 onwards with its use both as a semi-synthetic fibre and as a thermoplastic material for extrusion as a film. 

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