Rubber sodium

Iodine monochloride Aluminum foil, organic matter, metal sulfides, phosphorus, potassium, rubber, sodium... 

A substance added to latex in the preparation of pale crepe rubber sodium bisulphate prevents darkening of the crepe due to the presence of oxidising enzymes, xylyl mercaptan is an effective bleaching agent proper. 

NaHS03, is added to latex from which pale crepe rubber is to be made. It prevents discoloration of the crepe and destroys microorganisms which may cause later deterioration of the rubber. Sodium Dibutyl Dithiocarbamate SDBC, accelerator. 

Sodium is also used to make artificial rubber. (Real rubber is made from the collected sap of rubber trees and is expensive.) The starting material for artificial rubber is usually a small molecule. The small molecule reacts with itself over and over again. It becomes a much larger molecule called a polymer. The polymer is the material that makes up the artificial rubber. Sodium metal is used as a catalyst in this reaction. A catalyst is a substance used to speed up a chemical reaction without undergoing any change itself... 

Other synthetic emulsions include acrylics, which are widely used in pressure-sensitive adhesives for labels, polyurethanes, and synthetic rubbers. Sodium silicate was once widely used in paper packaging, but its only remaining major use is in tube winding, especially for large drums or cores. 

Silica, fumed Wollastonite filler, semi reinforcing rubber Sodium magnesium aluminosilicate... 

Polyacrylonitrile short stop, polymerization Potassium dimethyidithiocarbamate Sodium di-n-butyl dithiocarbamate Sodium dimethyidithiocarbamate short stop, rubber Sodium dibenzyidithiocarbamate shortening Vegetable oil shortening ingredient Linola oil shortening, food... 

Colourless liquid b.p. 69 5 C. Manufactured from propanone by conversion to pinacone and passing its vapour over heated KHSO4. Slowly changes to a rubber-like substance the change is hastened by metallic sodium or peroxides. Used in the manufacture of artificial rubber. 

Dimeihylamine, C2H7N, (CH3)2NH. Colourless, inflammable liquid with an ammoniacal odour, mp -96" C, b.p. 7°C. Occurs naturally in herring brine. Prepared in the laboratory by treating nitrosodimetbyl-aniline with a hot solution of sodium hydroxide. Dimethylamine is largely used in the manufacture of other chemicals. These include the solvents dimethylacetamide and dimethyl-formamide, the rocket propellant unsym-metrical dimethylhydrazine, surface-active agents, herbicides, fungicides and rubber accelerators. 

Carbon disulphide is an excellent solvent for fats, oils, rubber, sulphur, bromine and iodine, and is used industrially as a solvent for extraction. It is also used in the production of viscose silk, when added to wood cellulose impregnated with sodium hydroxide solution, a viscous solution of cellulose xanthate is formed, and this can be extruded through a fine nozzle into acid, which decomposes the xanthate to give a glossy thread of cellulose. 

For this reduction use preferably a i litre round-bottomed flask having 3 necks (Fig. 23(G), p. 46), the two necks at the flanks being straight (to avoid the obstruction, during the addition of sodium, which a curved neck might cause). Fit the central neck with a stirrer, one of the side necks with a reflux water-condenser, and the other with a glass or rubber stopper. 

Fit a 750 ml, bolt-head flask (also by a rubber stopper) to a reflux water-condenser closed at the top by a calcium chloride tube ensure that flask and condenser are quite dr). Place 150 ml. of the dried ethyl acetate in the flask and add 15 g. of sodium. The sodium for this purpose should preferably be added in the form of wire directly from a sodium press (Fig. 55, p. 82) alternatively the sodium may be added as thin slices, but in this case each slice should be quickly pressed between drying-paper before being added to the acetate to remove the wet film which may have formed during the weighing and cutting of the metal. 

Fit a three necked 250 ml. flask with a central rubber-sleeved or mercury-sealed stirrer, c/. Fig. 23(c), p. 45, where only two necks are shown, and with a thermometer the bulb of which reaches as near the bottom of the flask as the stirrer allows the third neck will carry at first a dropping-funnel and later a reflux condenser. Place 20 g. (19-5 ml.) of ethyl acetoacetate and 45 ml. of glacial acetic acid in the flask and by ice-water cooling adjust the temperature of the stirred mixture to 5 -7° maintain this temperature whilst adding a solution of 5 4 g. of sodium nitrite in 8 ml. of water slowly from the dropping-funnel during 15 minutes. Continue the stirring for 20-30 minutes, and then... 

This tube is connected %vith rubber tubing of about 6 mm. bore to the carbon dioxide Kipp, via a wash-bottle containing sodium carbonate solution (to remove any dilute hydrochloric acid spray). It is very important, when the apparatus is in use, that there should be no constriction or bend in the rubber tube between the tap C and the wash-bottle. If these precautions are taken, a slow, e en, and easily controlled flow of gas can be obtained. 

Old rubber stoppers may be used, but are slifthtly attacked. Asbestos-sodium silicate Stoppers (for preparation, see Section III,161,Note 2) or ground glass joints are, of course, to be preferred. 

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