Cellulose nitrate preparation

Sternberg LdSL, DeNiro MJ, Ajie HO (1986) Isotopic relatiortships between saporriliable hpids and cellulose nitrate prepared from red, brown and green algae. Planta 169 320-324 Sternberg LdSL (1988) D/H ratios of environmental water recorded by D/H ratios of plant lipids. Nature 333 59-61... 

The de Chardonnet (nitrocellulose) process was reported in 1884 to prepare cellulose nitrate cellulose nitrate prepared by this process continues to be an important commerical inorganic esier of cellulose. Originally, nitrocellulose was extruded to yield one of the first regenerated textile fibers. Principal uses of cellulose nitrate are in the manufacture of explosives, films, cements, lacquers and plastics. ... 

Cellulose nitrate prepared from paper by Pelouze. 

Glycerol ct-dichlorohydrin, sym-dichloroiso-propyl alcohol, 1,3-dichloro-2-hydroxypropane, CH2CI-CHOH-CH2C1. Colourless liquid with an ethereal odour b.p. 174-175" C. Prepared by passing dry HCl into glycerin containing 2% elhanoic acid at 100-1 lO C. Converted to x-epichlorohydrin by K.OH, Used as a solvent for cellulose nitrate and resins. 

Me2C = CHCOCH= CMca- Yellow liquid having a camphor-like odour m.p. 28 C, b.p. 198-5°C. It is formed when propanone is saturated with HCl and allowed to stand. Resembles camphor in many of its properties and is a solvent for cellulose nitrate. Used to prepare diisobutyl ketone (reduction). 

Cellulose Nitrate. Cellulose nitrate is prepared according to the following reaction ... 

Benoit et al.f prepared a mixture of two different fractions of cellulose nitrate and determined the molecular weight of the mixture by light scattering. The mixture was 25.8% by weight fraction A and 74.2% fraction B, where the individual fractions have the following properties ... 

Cellulose Deriva.tives, Cellulose can be derivatized to make both water-soluble gums and hydrophobic polymers. The preparation of the hydrophobic cellulose esters (qv), cellulose acetates and cellulose nitrates, has already been mentioned. The water-soluble cellulose derivatives are cellulose ethers (qv). 

In 1862 the Great International Exhibition was held in London and was visited by six million people. At this exhibition a bronze medal was awarded to Parkes for his exhibit Ptu kesine. This was obtained by first preparing a suitable cellulose nitrate and dissolving it in a minimum of solvent. The mixture was then put on a heated rolling machine, from which some of the solvent was then removed. While still in the plastic state the material was then shaped by dies or pressure . In 1866 the Parkesine Co., Ltd was formed but it failed in 1868. This appears in part due to the fact that in trying to reduce production costs products inferior to... 

Mineral-basal media may be sterilized by autoclaving, but for almost all organic compounds that are used as sources of C, N, S, or P, it is probably better to prepare concentrated stock solutions and sterilize these by filtration, generally using 0.2 pm cellulose nitrate or cellulose acetate filters. The same applies to solutions of vitamins, and to solutions of bicarbonate and sulfide that are components of many media used for anaerobic bacteria. 

Polyamide, collodion (cellulose nitrate), ethylcellulose, cellulose acetate butyrate or silicone polymers have been used for preparation of permanent microcapsules. This method offers a double specificity due to the presence of both the enzyme and a semipermeable membrane. Moreover, it allows simultaneous immobilization of many enzymes in a single step and the surface area for contacting the substrate and the catalyst is large. The need of high protein concentration and the restriction to low molecular weight substrates are the main limitations of enzyme microencapsulation. 

Uses Preparation of butyl esters (e.g., butyl acetate, di-n-butyl phthalate), glycol ethers solvent for waxes, resins, gums, and varnishes hydraulic fluid ingredient in perfumes and flavors additive in deicing fluids polishes, floor cleaners, stain removers, and in some gasolines (antiicing) diluent for brake fluids humectant for cellulose nitrate. 

Butanol, which at one time was an unwanted by-product in the preparation of acetone, is now the most important product of the fermentation. The building of a large new factory in Puerto Rico using 10,000 tons of molasses per annum for its production is an indication of this importance. Butanol is probably still the best solvent for cellulose nitrate lacquers. Dibutyl phthalate is certainly the most widely used plasticizer for synthetic resins, and butyl oleate, tributyl citrate and dibutyl tartrate have also been described as plasticizers. Another important use of butanol is as a source of butadiene, which serves as an intermediate in the conversion of sucrose into a synthetic rubber. Although in recent years other methods have been described for the preparation of butanol (for example, from ethyl alcohol and from acetylene), yet the fermentation of carbohydrates is still the cheapest process. 

The most important of the carbohydrate esters of nitric acid are the polysaccharide nitrates, particularly cellulose nitrate or nitrocellulose (NC) and starch nitrate ( nitrostarch ) which is much less used. Nitric esters prepared from other sugars such as saccharose and lactose are not of any importance as explosives. 

The separation of cellulose from the wood is carried out by one of three methods the soda process, the sulphate process, and the sulphite process. Nitration cellulose is prepared chiefly by the sulphite and sulphate methods. 

To broaden the scope of his interests, he spent another year as a postdoctoral fellow in the Physics Department of Pennsylvania State University, working on the X-ray analysis of biological compounds. Equipped with an exceptionally broad and multidisciplinary education and experience, he proceeded to The Ohio State University, Columbus, Ohio, to work with Professor M. L. Wolfrom. His initial job was to investigate the ignition of cellulose nitrate, a project left over from World War II. In Fred s hands, this project was turned into an isotopic investigation of the biosynthesis and degradation of cellulose. At this time, there was very little known about the preparation of specifically labeled sugars, let alone the biosynthesis of... 

The use of membranes for separating particles of colloidal dimensions is termed dialysis. The most commonly used membranes are prepared from regenerated cellulose products such as collodion (a partially evaporated solution of cellulose nitrate in alcohol plus ether), Cellophane and Visking. Membranes with various, approximately known, pore sizes can be obtained commercially (usually in the form of sausage skins or thimbles ). However, particle size and pore size cannot be properly correlated, since the permeability of a membrane is also affected by factors such as electrical repulsion when. the membrane and particles are of like charge, and particle adsorption on the filter which can lead to a blocking of the pores. 

An ingenious treatment of cellulose was discovered by Charles Cross and Edward Bevan in England in 1892. It involved first preparing a chemical derivative called cellulose xanthate in a process that is conceptually no different from converting cellulose into other derivatives such as cellulose acetate or cellulose nitrate. What made this different, however, is that xan-thates are reactive chemical intermediates that can be converted easily into still different compounds, or returned to the starting material, in this case cellulose. See Equation 3. 

Cellulose nitrate is usually prepared in nitrating acid mixtures containing besides nitric acid sulfuric acid as a catalyst. The first reaction step involves generation of the nitronium ion (N02 ) ... 

Cellulose acetate has replaced cellulose nitrate in many products, for example, in safety-type photographic films. When a solution of cellulose acetate in acetone is passed through the fine holes of a spinneret and the solvent evaporates, solid filaments are produced. Acetate rayon is prepared from threads of these filaments. Some applications and solvents of commercial cellulose acetate grades are summarized in Table 9-5. 

Cellulose nitrate can be prepared by treating highly purified cellulose with a mixture of nitric and sulfuric acid (6). The reaction scheme may be represented as shown in Scheme 2. 

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