Hydrogen peroxide, 90% concentration preparation

N-Oxidation of pyridazine with hydrogen peroxide and in the presence of sodium tungstate gives the JV-oxide in low yield. Peroxydichloromaleic acid is an efficient reagent for the preparation of pyridazine JV-oxides and polyhalogenated pyridazines are best N-oxidized with a mixture of hydrogen peroxide, concentrated sulfuric acid, and acetic acid or trifluoro-acetic acid. Some 3-aminopyridazines were transformed in a single... 

The PDMS (M = 6000 g/mol) and the carboxylated PDMS (CPDMS) were synthesized by Owens-Corning Corporation. The ionic groups (4.6 mol %) were randomly distributed along the PDMS chain. Lithium salts of the PDMS carboxylated ionomer (Li-CPDMS) were prepared by neutralizing the acid derivative with Lithium acetate dihydrate. The li ionomer was a rubbery solid at room temperature and exhibited viscous flow above 100°C. The substrates used were atomically smooth silicon wafers with a 100 orientation and one side polished. These were washed in an ultrasonic bath for 10 min. and then a 30/70 (v/v) concentrated hydrogen peroxide/concentrated sulfuric acid solution for 1 h. to clean the surface. The wafers were then rinsed thoroughly with deionized water and dried under a stream of dry nitrogen. Since silicon oxidizes very rapidly, the surface of the wafers that were used in these experiments was actually silicon dioxide (silica). 

The study of the chemical behavior of concentrated preparations of short-Hved isotopes is compHcated by the rapid production of hydrogen peroxide ia aqueous solutions and the destmction of crystal lattices ia soHd compounds. These effects are brought about by heavy recoils of high energy alpha particles released ia the decay process. 

Eatty amine oxides are most frequendy prepared from alkyldimethylarnines by reaction with hydrogen peroxide. Aqueous 2-propanol is used as solvent to prepare amine oxides at concentrations of 50—60%. With water only as a solvent, amine oxides can only be prepared at lower concentrations because aqueous solutions are very viscous. Eatty amine oxides are weak cationic surfactants. 

Methylsuccinic acid has been prepared by the pyrolysis of tartaric acid from 1,2-dibromopropane or allyl halides by the action of potassium cyanide followed by hydrolysis by reduction of itaconic, citraconic, and mesaconic acids by hydrolysis of ketovalerolactonecarboxylic acid by decarboxylation of 1,1,2-propane tricarboxylic acid by oxidation of /3-methylcyclo-hexanone by fusion of gamboge with alkali by hydrog. nation and condensation of sodium lactate over nickel oxide from acetoacetic ester by successive alkylation with a methyl halide and a monohaloacetic ester by hydrolysis of oi-methyl-o -oxalosuccinic ester or a-methyl-a -acetosuccinic ester by action of hot, concentrated potassium hydroxide upon methyl-succinaldehyde dioxime from the ammonium salt of a-methyl-butyric acid by oxidation with. hydrogen peroxide from /9-methyllevulinic acid by oxidation with dilute nitric acid or hypobromite from /J-methyladipic acid and from the decomposition products of glyceric acid and pyruvic acid. The method described above is a modification of that of Higginbotham and Lapworth. ... 

Tertiary butyl alcohol (900 ml., 702 g., 9.47 moles) is dissolved in a solution prepared by mixing 28 ml. (0.50 mole) of concentrated sulfuric acid with 1.5 1. of water in a 5-1. round-bottomed flask (Note 1) equipped with a thermometer, stirrer, gas inlet tube, and two addition burets. One buret is charged with 86 ml. (1 mole) of 11.6iH hydrogen peroxide (Note 2), and the other with a solution of 278 g. (1 mole) of ferrous sulfate pentahydrate and 55.5 ml. (1 mole) of concentrated sulfuric acid in 570 ml. of water (Note 3). The reaction flask is swept out with nitrogen and cooled to 10° by means of an ice bath. Stirring is commenced and the two solutions are added simultaneously and equivalently over a period of 20 minutes. The temperature is held below 20°. 

Discussion. With an acidic titanium(IV) solution hydrogen peroxide produces a yellow colour with small amounts oftitanium(up to 0.5 mg ofTiOz permL), the intensity of the colour is proportional to the amount of the element present. Comparison is usually made with standard titanium(IV) sulphate solutions a method for their preparation from potassium titanyl oxalate is described below. The hydrogen peroxide solution should be about 3 percent strength (ten volume) and the final solution should contain sulphuric acid having a concentration from about 0.75 to 1.75M in order to prevent hydrolysis to a basic sulphate and to prevent condensation to metatitanic acid. The colour intensity increases slightly with rise of temperature hence the solutions to be compared should have the same temperature, preferably 20-25 °C. 

Iodo-p-xylene has been prepared by the action of potassium iodide on diazotized p-xylidine (2,5-dimethylbenzenamine) (21% yield),5 from p-xylene with molecular iodine in concentrated nitric acid (50% yield)6 or in ethanol-sulfuric acid in the presence of hydrogen peroxide (64% yield),7 and with molecular iodine in glacial acetic acid-sulfuric acid in the presence of iodie acid as a catalyst (85% yield).8... 

Preparing peracetic acid by the action of hydrogen peroxide on acetic acid is as hazardous. If the temperature is too low, compounds accumulate and cause the medium to detonate. Using peracetic acid solution as an oxidant causes detonations when its concentration is too high or if evaporation is attempted. An accident happened during such an operation (see reaction below). The best way to eliminate this peracid at the end of the reaction is to heat it in a water bath at a temperature that should not exceed 50°C and under reduced pressure. 

The assessors experienced an explosion while drying the oxide in ethyl ether. Rather drastic precautions are recommended in handling it [1], A preparation, allowed to stand for a week rather than the day specified, exploded during concentration [2], Amine oxides from the standard preparation are inclined to retain hydrogen peroxide of hydration unless it is destroyed during work-up. The perox-idate (or diperoxidate) of dimethylamine oxide would be expected to be far more dangerous than the oxide itself [3],... 

The pure peroxoacid, prepared at —80°C, decomposes explosively at —30°C. Solutions in acetic acid or water of below the limiting concentration (corresponding to a stoicheiometric mixture of 70% aqueous nitric acid and 100% hydrogen peroxide) are stable, while those above the limit decompose autocatalytically, eventually exploding [1], Explosion of the vapour when passed into a mass spectrometer inlet at 427°C (but not at 327°) was noted [2],... 

Latex or emulsion polymers are prepared by emulsification of monomers in water by adding a surfactant. A water-soluble initiator is added, e.g., persulfate or hydrogen peroxide (with a metallic ion as catalyst), that polymerises the monomer yielding polymer particles, which have diameters of about 0.1 pm. The higher the concentration of surfactant added, the smaller the polymer particles. 

---