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Cellulose Acetate At about the same time, Little in the US and Bronnert in Germany simultaneously produced cellulose acetate filaments, which were in actual fact cellulose triacetate, which differs in that it is does not easily dissolve on common solvents. Cellulose acetate fibres are used for textiles and clothing by many of the top designers in the world. Cellulose triacetate has been the material of favour for photographic film since about 1940. www.azom.com /details.asp?ArticleID=1461   (401 words)

SAA: Glossary of Archival Terminology Cellulose diacetate was commonly used as the base of photographic and motion picture films beginning in the early 20th century. Use of cellulose triacetate as a film base was largely, but not entirely, superseded by polyester beginning in the 1950s. 2000): Cellulose acetate is the generic term used to describe a variety of acetylated cellulose polymers, including cellulose diacetate, cellulose triacetate and the mixed esters of cellulose acetate propionate and cellulose acetate butyrate. www.archivists.org /glossary/term_details.asp?DefinitionKey=1945   (135 words)

Cellulose Acetate Although cellulose acetate was first prepared in 1865 by the French chemist Paul Schützenberger, it was not until 1894 that the first industrial process for its manufacture was patented in the UK by Charles Cross and Edward Bevan. Cellulose acetate (CA) in combination with plasticizers, such as diethyl and dimethyl phthalate, produces a plastics material which can be heat softened and forced under pressure into a cool mould. Ironically, cellulose triacetate which was unsuccessful initially, returned to favour when a suitable, relatively non-toxic solvent (dichloromethane) became available in the 1940s. www.plastiquarian.com /ca2.htm   (593 words)

Cellulose triacetate - Wikipedia, the free encyclopedia It is similar chemically to cellulose acetate, with the distinguishing characteristics being that in triacetate, according to the Federal Trade Commission definition, at least "92 percent of the hydroxyl groups are acetylated". Triacetate is derived from cellulose by combining cellulose with acetate from acetic acid and acetic anhydride. The cellulose acetate is dissolved in a mixture of dichloromethane and methanol for spinning. en.wikipedia.org /wiki/Cellulose_triacetate   (335 words)

Cellulose - Wikipedia, the free encyclopedia Cellulose is not digestible by humans, and is often referred to as 'dietary fiber' or 'roughage', acting as a hydrophilic bulking agent for faeces. Cellulose is used within the laboratory as a solid-state substrate for thin layer chromatography, and cotton linters, is used in the manufacture of nitrocellulose, historically used in smokeless gunpowder. Cellulose can be assayed using a method described by Updegraff in 1969, where the fiber is dissolved in acetic and nitric acid, and allowed to react with anthrone in sulfuric acid. en.wikipedia.org /wiki/Cellulose   (933 words)

Two-pass Combined Membrane Reverse Osmosis Water Treatment Combining cellulose triacetate and polyamide membranes in the first and second passes, respectively, is just one approach that offers some interesting advantages, but it may not necessarily be suitable for all applications of two-pass reverse osmosis. In the end, it makes sense to use cellulose triacetate as a "roughing" filter, followed by polyamide to provide the "final" polish to deal with removal of inorganics that are not highly rejected by the cellulose triacetate, such as silica. If the cellulose triacetate is providing high rejection and the second pass is designed at a relatively low recovery (for example, 80 percent), such a problem should not arise. www.environmental-expert.com /articles/article329/article329.htm   (2904 words)

Making Rayon Fiber   (Site not responding. Last check: 2007-10-21) Steeping: Cellulose pulp is immersed in 17-20% aqueous sodium hydroxide (NaOH) at a temperature in the range of 18 to 25° C in order to swell the cellulose fibers and to convert cellulose to alkali cellulose. The orange cellulose xanthate crumb is dissolved in dilute sodium hydroxide at 15 to 20° C under high-shear mixing conditions to obtain a viscous orange colored solution called "viscose", which is the basis for the manufacturing process. Once the cellulose xanthate is neutralized and acidified, rapid coagulation of the rayon filaments occurs which is followed by simultaneous stretching and decomposition of cellulose xanthate to regenerated cellulose. www.mindfully.org /Plastic/Cellulose/Rayon-Fiber.htm   (2855 words)

Organophosphorus Flame Retardants,Flame Retardant Plasticizers,Organophosphorus Flame Retardants Supplier,Flame ... Others important properties are its toughening ability and extremely low volatility in cellulose acetate and triacetate, its good resistance to extremely low volatility in cellulose Acetate and triacetate its good resistance to moisture, and its lack of odour. In secondary cellulose acetate, cellulose acetate butyrate, and ethyl cellulose, for film sheeting or moulding material, it is generally combined with other more active plasticizer such as dimethyl phthalate, dimethoxy ethyl phthalate or diethyl phthalate. Typical moulding applications of triphenyl phosphate are in cellulose acetate, cellulose acetate butyrate, and vinyl copolymer compound which are used in records, vacuum cleaner parts, housings for clocks and appliances, and parts for Christmas tree lighting sets. www.pac-india.com /organo-phosphate-esters.html   (1005 words)

[No title]   (Site not responding. Last check: 2007-10-21) Cellulose acetates are used in lacquers and protective coatings for various substrates such as paper, glass, metal, leather, and wood. Cellulose acetate flake consumption is presented for four regions in 1997 and 2002. Cellulose acetate demand is flat or declining in developed regions and growing slightly in developing regions, resulting in little overall growth. www.chemsystems.com /newsletters/perp/Jun04_N03S1.cfm   (1881 words)

Preserving Your Collection of Film-Based Photographic Negatives Recent research indicates that all cellulose-based film, whether it's a cellulose nitrate negative from the 1890's or a cellulose triacetate color transparency from the 1990's, share very similar deterioration mechanisms that are temperature and humidity dependent. Cellulose triacetate remains in use today, though within the past few years, stability problems have come to light with it as well. Diacetate and triacetate characteristically form deep, wavy grooves in the film base known as "channelling." This condition is the result of the film base shrinking in relation to the gelatin emulsion. palimpsest.stanford.edu /byauth/messier/negrmcc.html   (3064 words)

Nature of Materials: Film   (Site not responding. Last check: 2007-10-21) Used mainly for 16-millimeter film after about 1923, cellulose acetate is made from various forms of cellulose fiber combined with acetic acid, acetic anhydride, and, as a catalyst, sulfuric acid. Cellulose diacetate was first made by Kodak, from 1925 to 1940, and Agfa continued to make it until 1955. Cellulose triacetate, more durable than diacetate, gradually replaced it in the late 1940s. www.librarypreservation.org /preservation/film.htm   (382 words)

Reverse Osmosis Water Treatment Cellulose acetate membranes are inexpensive and easy to manufacture but suffer from several limitations. Cellulose acetate membranes are susceptible to hydrolysis and can only be used over a limited pH range (low pH 3 to 5 and high pH 6 to 8, depending on the manufacturers). Cellulose triacetate membranes have been developed with improved salt rejection characteristics and reduced susceptibility to pH, high temperature and microbial attack. www.aquatechnology.net /reverse_osmosis.html   (2863 words)

Acetate filament yarns in rawwhite and spundyed for textiles The Dreyfus brothers initially focused on cellulose acetate film, which was then widely used in celluloid plastics and motion picture film. Cellulose acetate is a man made fibre of natural origin with specific characteristics which allow the production of beautiful, practical and comfortable fabrics, whether used on its own or mixed with other natural, artificial or synthetic yarn or fibres Triacetate fibers are fibers to which more acetic acid is combined than to acetate fibers. www.swicofil.com /products/204acetate.html   (616 words)

Triacetate Fiber - Triacetate Staple Fiber, Triacetate Filter Tow Fiber, Triacetate Textile Filament Fiber — Triacetate is derived from cellulose by combining cellulose with acetate from acetic acid and acetate anhydride. The cellulose acetate is dissolved in a mixture of methylene chloride and methanol for spinning. As the filaments emerge from the spinneret the solvent is evaporated in warm air — dry spinning —; leaving a fiber of almost pure cellulose acetate. www.fibersource.com /f-tutor/triacetate.htm   (184 words)

Care & Identification of Film-Base Photographic Materials   (Site not responding. Last check: 2007-10-21) Neither cellulose nitrate or cellulose diacetate appear to deteriorate significantly faster than other cellulosic film materials.(l l) This research suggests that negative condition and not negative type should be the criterion for duplication. This is particularly true of cellulose acetates; their condition can go from an undeteriorated state to a badly deteriorated one in a matter of months, even in fairly good environments. The nitric acid produced by the degradation of cellulose nitrate may cause deterioration characteristics of cellulose nitrate (such as image fading and stickiness) to be seen in cellulose acetates and polyester. palimpsest.stanford.edu /byauth/fischer/fischer1.html   (2964 words)

Cellulose Triacetate Ultrafiltration Cassettes The cellulose triacetate membrane is a membrane polymer that is well established in the biotechnological and pharmaceutical industries. The cellulose triacetate membrane is extremely hydrophilic, making it virtually non-protein-binding. Cellulose triacetate membranes are designed for use in the biotechnological and pharmaceutical industries. www.pharmaceuticalonline.com /Content/ProductShowcase/product.asp?DocID={2E7AD5D9-48EB-4B98-B5AA-A4D2725D4FEC}   (107 words)

HDCN: Review of article by Hakim et al. Effect of the dialysis membrane on mortality of chronic ... Membranes were divided into 3 groups: unsubstituted cellulose, modified cellulose (which includes hemophan, cellulose acetate, and cellulose triacetate), and synthetic (primarily polysulfone and PAN). Unsubstituted cellulose membranes were excluded from the NIH HEMO trial, in an attempt to separate out flux and biocompatibility issues. I don't believe that the case against unsubstituted cellulose membranes is a strong one in 1996, certainly not in terms of mortality. www.hdcn.com /6/608kihak.htm   (599 words)

PHOTOGRAPHS Triacetate is still used as a film base today in conjunction with polyester film which was introduced in 1960.Made of cellulose acetate plastic, this film is harder to ignite and is self-extinguishing. Cellulose acetate film is also known as ‘safety film’; because it was developed to avoid the high risks associated with nitrate film. Triacetate is relatively more stable than diacetate, but it too may develop vinegar syndrome as it ages. www2.hawaii.edu /~dianey/photos.htm   (5892 words)

From Cotton to Cellulose Acetate cellulose, which is a polymer of glucose and grown by special plants. Cellulose in trees is combined with two other components, hemicellulose (to fill in the empty places) lignin (the glue that binds it all together). One of the uses of cellulose acetate is in candy wrappers. www.pslc.ws /macrog/proposal/dreyfus/outcome/plascot/cellace.htm   (828 words)

ISO/ASTM51650-05 Standard Practice for Use of Cellulose Acetate Dosimetry Systems 1.1 This practice covers procedures for using the cellulose triacetate (CTA) dosimetry system for measuring absorbed dose and dose profile in materials irradiated by electrons and photons in terms of absorbed dose to water. Cellulose triacetate dosimeter refers to untinted film dosimeter. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. www.astm.org /DATABASE.CART/PAGES/ISOASTM51650.htm   (235 words)

Cellulose acetate - Wikipedia, the free encyclopedia It is then put through a controlled, partial hydrolysis to remove the sulfate and a sufficient number of acetate groups to give the product the desired properties. The anhydroglucose unit is the fundamental repeating structure of cellulose and has three hydroxyl groups which can react to form acetate esters. In England, in 1912, the British company produced the first commercial cellulose acetate yarn. en.wikipedia.org /wiki/Cellulose_acetate   (1586 words)

That Smell in the Vaults: The Degradation of Polymers in AV Materials All polymers are subject to decay; and the cellulose nitrate, cellulose diacetate, cellulose butyrate, cellulose propionate and cellulose triacetate bases are no exception. The base of motion picture film consists of a backbone of hydroglucose molecules chained together in long strings with additional chemical groups included; nitrate in cellulose nitrate, or acetate in cellulose acetate, cellulose diacetate or cellulose triacetate film. Vinegar Syndrome - describes the odor given off by the decomposition of the cellulose triacetate base. www.kinema.uwaterloo.ca /ritch951.htm   (2427 words)

Studies on enzyme electrodes with ferrocene and carbon paste bound with cellulose triacetate. Studies on enzyme electrodes with ferrocene and carbon paste bound with cellulose triacetate. Beh, S. K.; Moody, G. J.; Thomas, J. Studies on enzyme electrodes with ferrocene and carbon paste bound with cellulose triacetate. A simplex optimization procedure was used in evaluating electrodes without the use of an exclusion membrane. www.multisimplex.com /dbase/16.htm   (104 words)

KODAK: H-1 Base - Print Friendly Version (The words triacetate and acetate will be used interchangeably throughout this guide.) Cellulose triacetate photographic film base is made by combining the cellulose triacetate with suitable solvents and a plasticizer. Permanent shrinkage of film on cellulose triacetate support is usually due to loss of residual solvents or plasticizers and, to a slight extent, the gradual elimination of strains introduced during manufacture or processing. ESTAR Base has no residual solvent or plasticizer and absorbs less moisture than cellulose triacetate; consequently, its size changes due to aging are less. www.kodak.com /US/en/motion/support/h1/baseP.shtml   (2219 words)

Diffusion and Saponification Inside Porous Cellulose Triacetate Fibers   (Site not responding. Last check: 2007-10-21) Cellulose triacetate (CTA) fibers were partially hydrolyzed in 0.054 N solutions of NaOH/H The surface concentration of acetyl groups was determined using ATR-FTIR. Similarities between calculated concentration profiles for each case indicate that the relatively diffuse interface seen in fibers from the NaOMe/MeOH reaction results from factors not considered in the model; shrinkage of stained fiber cross-sections suggests that increased disruption of intermolecular forces may be the cause. pubs.acs.org /cgi-bin/abstract.cgi/bomaf6/2005/6/i01/abs/bm0496413.html   (240 words)

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