Dry benzoyl peroxide

Dry benzoyl peroxide (05115002)2 is easily ignited and sensitive to shock. It decomposes spontaneously at temperatures above 50 °C. It is reported to be desensitized by addition of 20% water. 

A typical process for the preparation of a poly(methyl methacrylate) suspension polymer involves charging a mixture of 24.64 parts of methyl methacrylate and 0.25 parts of benzoyl peroxide to a rapidly stirred, 30°C solution of 0.42 parts of disodium phosphate, 0.02 parts of monosodium phosphate, and 0.74 parts of Cyanomer A-370 (polyacrylamide resin) in 73.93 parts of distilled water. The reaction mixture is heated under nitrogen to 75°C and is maintained at this temperature for three hours. After being cooled to room temperature, the polymer beads are isolated by filtration, washed, and dried (69). 

Benzoyl peroxide [94-36-0] M 242.2, m 95°(dec). Dissolved in CHCI3 at room temperature and ppted by adding an equal volume of MeOH or pet ether. Similarly ppted from acetone by adding two volumes of distilled water. Has also been crystd from 50% MeOH, and from diethyl ether. Dried under vacuum at room... 

Vinyl acetate [108-05-4] M 86.1, b 72.3 , d 0.938, n 1.396. Inhibitors such as hydroquinone, and other impurities are removed by drying with CaClj and fractionally distilling under nitrogen, then refluxing briefly with a small amount of benzoyl peroxide and redistilling under nitrogen. Stored in the dark at 0 . 

The cure reaction of structural acrylic adhesives can be started by any of a great number of redox reactions. One commonly used redox couple is the reaction of benzoyl peroxide (BPO) with tertiary aromatic amines. Pure BPO is hazardous when dry [39]. It is susceptible to explosion from shock, friction or heat, and has an autoignition temperature of 79°C. Water is a very effective stabilizer for BPO, and so the initiator is often available as a paste or a moist solid [40], The... 

Aluminum chlorate Ammonium chromate Benzoyl peroxide, dry... 

Dilute nitric acid instead of concentrated fuming nitric acid — Wet benzoyl peroxide instead of dry... 

A 250-ml round-bottom flask is fitted with a condenser (drying tube), a magnetic stirrer, and a heating mantle. The flask is charged with 8.2 g (0.1 mole) of cyclohexene, 14 g (0,079 mole) of NBS, 0.1 g of benzoyl peroxide, and 50 ml of dry carbon tetrachloride. The flask is flushed with nitrogen and then refluxed for 40 minutes with... 

Prepn is by dropwise addn of a cold aq sodium peroxide (1.0 molar) so In to 1.0 mole of vigorously stirred ethyl chloroformate while maintain, ing the temp at 6— 10°. The mixt is stirred for an addnl half hr after all the sodium peroxide has been added. The oily prod is then sepd, washed with distd w and dried using anhyd Naj S04. An 81 % yield is obtd. The frozen ester is sens to the shock from a No 6 elect detong cap, producing a more brisant deton than an equal amt (0.25 lb) of benzoyl peroxide Ref F. Strain et al, JACS 72,1254-63 (1950) CA 46,1984(1950)... 

Vinyl Acetate CH3COOCH=CH2 OH compds, HCN, Halides, Halogens, Mer-cap tans, Amine, Silanes Oxygen Vap in Air 2.6 to 13.4% > Ambient > Ambient Inhibitor—Methyl Ether of Hydroquinone or 3-5ppm Diphenylamine. Store in a dry, cool place shield from light impurities 20.9-21.5 402 427 Free-radical polymerization initiated by Benzoyl Peroxide... 

Wheat flour typically becomes white by means of normal oxidation in air during a few weeks of storage. To speed up the process, manufacturers use benzoyl peroxide as a bleaching agent. Sulfur dioxide is a reducing bleaching agent that is used to preserve dried fruits. 

A typical regimen for benzoyl peroxide use is to apply the product to clean, dry skin no more than two times a day. The strength and dosage form selected may vary from patient to patient depending on acne severity and the sensitivity of the patient s skin. Since gel preparations are the most potent dosage form, patients with dry or overly sensitive skin should... 

Bulk and suspension polymerisation are the most commonly used techniques. In bulk polymerisation styrene is heated to 80°C for about 2 days to get a viscous solution of polymer in styrene. The solution is then fed to a tower wherein polymerisation is completed at 100°C, 150C° and 180C° stagewise. In suspension process, styrene is suspended in dimineralised water in presence of suspending agent and initiator like benzoyl peroxide and heated to 20°C. The product is washed with acid, water and dried. 

Preparation of Benzoyl Peroxide.1—Hydrogen peroxide (50 c.c. of about 10 per cent aqueous solution) kept well cooled in ice and continually shaken (preferably in a glass-stoppered bottle) is treated alternately with 4 A-sodium hydroxide solution and benzoyl chloride, added each a few drops at a time the solution is maintained faintly alkaline throughout. After about 30 c.c. of alkali and 15 g. of benzoyl chloride have been used up, the hydrogen peroxide has been decomposed and the benzoyl peroxide has separated in crystalline flocks, while the odour of the chloride has almost completely disappeared. The peroxide is filtered with suction, washed with water, and dried. Yield 10-12 g. Crystallised from a little alcohol, with which it should be boiled for a short time only, the substance forms beautiful colourless prisms. Melting point 106°-108° decomp. Heat a small quantity rapidly in a dry test tube over a naked flame. An especially pure product is obtained when a 1 von Pechmann and Vanino, Ber., 1894, 27, 1510. 

Reactivity. Chemicals that react violently with air or water are considered hazardous examples are sodium metal, potassium metal, and phosphorus. Reactive materials also include strong oxidizers such as perchloric acid, and chemicals capable of detonation when subjected to an initiating source, such as solid, dry < 10% H2O picric acid, benzoyl peroxide, or sodium borohydride. Solutions of certain cyanide or sulfides that could generate toxic gases are also classified as reactive. The potential for finding such chemicals in a refinery is... 

To a 1-1., three-necked, round-bottomed flask is added 7.2 g. (0.15 mole) of a 50% dispersion of sodium hydride in mineral oil (Note 1). The sodium hydride is washed several times by decantation with dry ether and is then covered with 300 ml. of dry benzene (Note 2). The flask is equipped with dropping funnel, stirrer, and reflux condenser. Diethyl ethylmalonate (28.2 g., 0.15 mole) (Note 1) is added dropwise over a 5-minute period, and the reaction mixture is stirred for 2 hours until a clear solution forms. The solution is cooled in an ice bath, and 24.2 g. (0.1 mole) of benzoyl peroxide (Note 3) in 300 ml. of dry benzene is added dropwise over a 1-hour period with continuous stirring After another 30 minutes, a peroxide test (Note 4) is made to ensure that all the peroxide has reacted. 

Polymer Preparation. Polymers were typically prepared in ethyl acetate solution at reflux temperature using benzoyl peroxide as initiator. They were isolated by two precipitations from ethyl acetate solution into methanol and were dried under vacuum. Molecular parameters of the polymers prepared are listed in Table II. Materials ... 

Acrylated lignin derivatives were copolymerized with MMA and S in dry methylene chloride with benzoyl peroxide and N,N-dimethyl anyline as catalyst. Reaction mixtures were poured onto Teflon molds, the solvent was evaporated at room temperature in the fume hood, and films were cured in an oven at 105°C for 6 hrs. Experimental details and results are given elsewhere (15). 

---