Nitrite rubber

CAS 21645-51-2 EINECS/ELINCS 244492-7 Uses Flame retardant, smoke suppressant tor plastics, rubber, paper, adhesives, coatings, flexible and rigid PVC, nitrite rubbers, neoprene, polyolefins, EPDM, SBR, EPR, latexes, urethanes, EVA copolymers, unsat. polyesters, etc. polishing agent for dentifrices approved for internal use... 

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... 

Rubber Chemicals. Sodium nitrite is an important raw material in the manufacture of mbber processing chemicals. Accelerators, retarders, antioxidants (qv), and antiozonants (qv) are the types of compounds made using sodium nitrite. Accelerators, eg, thiuram [137-26-8J, greatly increase the rate of vulcaniza tion and lead to marked improvement in mbber quaUty. Retarders, on the other hand (eg, /V-nitrosodiphenylamine [156-10-5]) delay the onset of vulcanization but do not inhibit the subsequent process rate. Antioxidants and antiozonants, sometimes referred to as antidegradants, serve to slow the rate of oxidation by acting as chain stoppers, transfer agents, and peroxide decomposers. A commonly used antioxidant is A/,AT-disubstituted Nphenylenediamine which can employ sodium nitrite in its manufacture (see Rubber chemicals). 

NMOR is a potent hepatocarcinogen in the rat and induces tracheal and nasal cavity tumors in the Syrian golden hamster (43, 44, 45). It is formed readily from nitrite and morpholine in vitro and administration of these precursors to rodents causes tumors indicative of NMOR formation in vivo (44, 55, 56), NMOR has been detected in crankcase emissions of diesel engines and in factories engaged in rubber and tire manufacturing (57, 58). 

Rubber-bonded grinding wheels, 1 19 Rubber chemicals, sodium nitrite in, 22 858-859... 

An apparatus for producing pure nitric oxide is set up as follows. As in the apparatus for preparing hydrogen chloride, a filter flask (capacity 750 c.c.) is fitted with a dropping funnel, from which 42V-sulphuric acid is dropped into concentrated sodium nitrite solution, containing 70 g. of NaN02 in 150 c.c. of water. For this amount of nitrite 250 c.c. of the 42V-acid are required. The side tube of the flask leads first to a wash-bottle with concentrated sodium (or potassium) hydroxide, and then to one with concentrated sulphuric acid. By means of a short rubber tube a T-tube is attached to the second wash-bottle. One branch of the tube is connected to a carbon dioxide Kipp, the other to the reaction vessel. The rubber tube carries a screw clip so that, at the end of the experiment, the nitric oxide generator can be removed. 

Volatile nitroso compounds were determined in hams processed in elastic rubber nettings by SPE and GC-CLD577. By a similar method A-n i tro sodi ben zy lamine (278b), a semivolatile nitrosamine, was determined in these products by SPE followed by GC interfaced to a nitrosamine-specific TEA-CLD detector the coefficient of variation was 10.6% at the 2.1 ppb level578. The nitrosamines detected in ham most likely originate from the amine precursors in rubber and from the nitrite commonly used in the meat curing process. 

A dry 250-ml., one-necked, round-bottomed flask is equipped with a magnetic stirrer and a three-way stopcock. The flask is charged with 4 g. (0.053 mole) of ethyl nitrite (Note 1), 4 g. of dry tetrahydrofuran (Note 2), and 2.35 g. (0.033 mole) of pyrrolidine (Note 3) The stopcock is closed (Note 4), and the mixture is stirred at room temperature for 2 days Excess ethyl nitrite, tetrahydrofuran, and the ethanol formed are removed from the N-nitrosopyrrolidine (Note 5) by stirring at 25° under reduced pressure (10 mm., water aspirator, Note 6) for 2 hours. The stopcock is fitted with a rubber septum, the air in the system is replaced by dry argon (Notes 4 and 7), and 50 ml. of tetrahydrofuran is injected by syringe. A solution of lithium diisopropylamide is prepared in a separate dry 100-ml. flask by adding 21.1 ml (0 034 mole) of a 1.61 M solution of butyllithium in hexane (Note 8) to a solution of 4.76 ml. (0.034 mole) of diisopropylamine (Note 9) in 25 ml of tetrahydrofuran at -78° (dry ice-methanol bath) with... 

Rubber chemicals - [RUBBERCHEMICALS] (Vol 21) -potassium hydroxide m mfg of [POTASSIUM COMPOUNDS] (Vol 19) -sodium nitrite for [SODIUM COMPOUNDS - SODIUM NITRITE] (Vol 22)... 

Preparation of m-Nitrobenzene.diazonium Perchlorate. Half a gram of m-nitroaniline is suspended in 5 ec. of water in a wide test tube, and 0.5 cc. of concentrated hydrochloric acid and 2.2 cc. of 20% perchloric acid solution are added. After the nitraniline has dissolved, 15 cc. of water is added and the solution is cooled by immersing the test tube in a beaker filled with a slurry of cracked ice. One-quarter of a gram of sodium nitrite dissolved in 1 or 2 cc. of water is added in 3 or 4 portions, the mixture being shaken after each addition or stirred with a stirring rod the end of which is covered with a short piece of rubber tubing. After standing in the cold for 5 minutes, the material is transferred to a filter, and the feltlike mass of pale yellow needles is washed with cold water, with alcohol, and with ether. The product is dried in several small portions on pieces of filter paper. 

NaN, is used as an initiator for emulsion polymerization (Ref 137), as a cellulating agent (Ref 134) and as a retarder (Ref 185) in the manuf of sponge rubber. The addn of NaN, an alkali bicarbonate and an alkali to form a compn of pH 9-12 prevents or reduces plating out or coagulation of styrene and butadiene latexes stored in contact with metals (Ref 162). NaN, is used also to decomp nitrites in the presence of nitrates (Ref 172). The rate of nitrite decompn is increased with an increase in azide concn. Acosta (Ref 172) detd the optimum ratio to be CNaN,/CNaNO, 3-9- Compds of the structure R,R (- 0) (- NH) have been prepd from the corresponding sulfoxide and NaN, + H,S04 in chlf soln (Ref 171) ... 

Small Quantities. Wear nitrile rubber gloves, laboratory coat, and eye protection. Work in the fume hood. Add water (0.7 mL), concentrated hydrochloric acid (2.1 mL), and benzidine (1.5 g, 0.0057 mol) to 50-mL, three-necked, round-bottom flask equipped with stirrer, thermometer, and dropping funnel. Maintain temperature at -5 to 0°C by a cooling bath, while adding dropwise 0.43 g (0.006 mol) of 97% sodium nitrite dissolved... 

Wear eye protection, laboratory coat, and nitrile rubber gloves. Scoop into a pail of water. In the fume hood, slowly add a freshly prepared 10% solution of sodium bisulfite or sodium metabisulfite (50 mL/g or 75 mL/g, respectively). Test for presence of nitrite using starch-iodide paper dipped in dilute acetic acid.7 When nitrite is completely destroyed, decant the liquid to the drain.6 Spill site should be washed thoroughly with water to remove all oxidant, which is liable to render any organic matter (e.g., wood, paper, textiles) dangerously combustible when dry. Clothing wetted with the solution should be removed and washed immediately.2... 

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