Collodions substances

The substances generally used as osmotic membranes include collodion (nitrocellulose of 11-13.5 per cent nitrogen) regenerated cellulose, obtained by denitration of collodion gel cellophane that has never permitted to dry after manufacture bacterial cellulose, obtained by the action of certain strains of bacteria rubber, poly (vinyl alcohol) polyurethances poly (vinyl butyral) and polychlorotrifluoroethylene. At present gel cellophane is most widely used. 

The development of plastics accompanied synthetic fibers. The first synthetic plastic with the trade name Celluloid was made in 1870 from a form of nitrocellulose called pyroxylin, the same substance used to produce the first rayon. Celluloid was developed in part to meet the demand for expensive billiard balls, which at the end of the nineteenth century were produced from ivory obtained from elephant tusks. John Wesley Hyatt (1837-1920) combined pyroxylin with ether and alcohol to produce a hard substance called collodion. Hyatt s collodion, like Bernigaut s original rayon, was unstable and potentially explosive. He solved this problem by adding camphor to the collodion to produce a stable hard plastic he called Celluloid. 

Franke patented in France in 1886, mixtures of nitrated benzene, phenol, naphthalene or naphthol with solid oxidizers, using as binders non-explosive substances, such as drying oils, soln of collodion or of gum, etc Ref Daniel, Diet (1902), 309... 

The operation proceeds as follows a brass mesh and a linen disk are put on the bottom of a cylinder at position 1, and then 20 kg (dry substance) of wet nitrocellulose is poured in from above. Commonly used types of nitrocellulose (guncotton with collodion cotton) are packed alternately in layers, which in fact... 

The cotton thus prepared takes the name of Xyloidin, and may afterwards be mixed with tire ether and the other substances which form it into elastic collodion. 

The Collodion Processes, Positive and Neua-tive.—Collodion, so named from its adhesive nature, is a gelatinous substance made by dissolving pyroxylin -gun-cotton—in a mixture of ether and alcohol. It is extensively used in photography, as a vehicle for supporting the sensitive chemicals. 

Hackel has extended Hibbert s observations concerning the influence of certain substances on the formation of nitroglycerine crystals of different forms. Thus, adding urethane, phenylurethane, collodion, nitrocotton, cyclonite, tetryl, dinitrobenzene, or centralites I and II promotes the formation of the labile form. Admixtures of siliceous earth, trinitrobenzene, TNT, favour the creation of the stable form. 

Treated wilh nitric acid under various conditions, coiton yields a long series of by-products. Some of them are plastic substances. If highly nitrated, cellulose becomes gun-eoiton. used in the manufacture ol explosives. Collodion is one of these nitrated products. Many varnishes and lacquers are made from collon cellulose. 

Cartridge Shells of Easily Combustible Substances, The material consists of very loosely woven cotton or silk tissue, which is impregnated with nitroglycerine, or with a mixture of sulphur and saltpetre. When the tissue is dry. collodion, to which a small quantity or castor oil has been added, is poured over it and it is then smoothed between... 

Ammonium lilmote or Ammonium Humote is a substance obtained in 1889 1 Gaens on boiling peat(previously washed) with a soln of Na,COj. An expl mixt contg this "ulroate , KNOj and collodion cotton(gelatinized by... 

The preceding discussion of the industrial products obtained from cellulose while not complete nor in technical detail emphasizes the striking fact that cellulose, a widely distributed natural substance, complex in its constitution and inactive in its properties, may, by either mechanical treatment or chemical reaction, be converted into such important products as thread, string and rope wearing apparel (cotton and linen). Mercerized cotton, artificial silk collodion, celluloid, smokeless powders and high explosives. 

Paints, medicinal Liquid medicinal preparations possessing antiseptic, caustic, soothing, or stimulating properties, usually applied by means of a brush. Paints intended to remain in contact with a specified surface are usually prepared with collodion, glycerin, glycerin and water, egg albumin in alcohol, or gutta percha. Paints intended to be absorbed are prepared with oleic acid or fatty oils. Caustic substances are usually applied dissolved in distilled water, alcohol, or ethereal vehicles, whereas resinous substances, such as benzoin. 

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