Potassium persulfate oxidant

The kinetics of aqueous dispersion polymerization differ very little from acrylonitrile bulk or emulsion polymerization. Redox initiation is normally used in commercial production of polymers for acrylic fibers. This type of initiator can generate free radicals in an aqueous medium efficiently at relatively low temperatures. The most common redox system consists of ammonium or potassium persulfate (oxidizer), sodium bisulfite (reducing agent), and ferric or ferrous iron (catalyst). This system gives the added benefit of supplying dye sites for the fiber. 

An example of a continuous aqueous dispersion process is shown in Figure 12.5 [92]. A monomer mixture composed of acrylonitrile and up to 10% of a neutral comonomer, such as methyl acrylate or vinyl acetate, is fed continuously. Polymerization is initiated by feeding aqueous solutions of potassium persulfate (oxidizer), sulfur dioxide (reducing agent), ferrous iron (promoter), and sodium bicarbonate (buffering agent). The aqueous and monomer feed... 

Sahcylaldehyde is readily oxidized, however, to sahcyhc acid by reaction with solutions of potassium permanganate, or aqueous silver oxide suspension. 4-Hydroxybenzaldehyde can be oxidized to 4-hydroxybenzoic acid with aqueous silver nitrate (44). Organic peracids, in basic organic solvents, can also be used for these transformations into benzoic acids (45). Another type of oxidation is the reaction of sahcylaldehyde with alkaline potassium persulfate, which yields 2,5-dihydroxybenzaldehyde (46). 

Methylene iodide [75-11-6], CH2I2, also known as diio dome thane, mol wt 267.87, 94.76% I, mp 6.0°C, and bp 181°C, is a very heavy colorless Hquid. It has a density of 3.325 g/mL at 20°C and a refractive index of 1.7538 at 4°C. It darkens in contact with air, moisture, and light. Its solubiHty in water is 1.42 g/100 g H2O at 20°C it is soluble in alcohol, chloroform, ben2ene, and ether. Methylene iodide is prepared by reaction of sodium arsenite and iodoform with sodium hydroxide reaction of iodine, sodium ethoxide, and hydroiodic acid on iodoform the oxidation of iodoacetic acid with potassium persulfate and by reaction of potassium iodide and methylene chloride (124,125). Diiodoform is used for determining the density and refractive index of minerals. It is also used as a starting material in the manufacture of x-ray contrast media and other synthetic pharmaceuticals (qv). 

Organic selenium compounds and siUceous materials (rock, ore, concentrates) are fused with mixtures of sodium carbonate and various oxidants, eg, sodium peroxide, potassium nitrate, or potassium persulfate. For volatile compounds, this fusion is performed in a bomb or a closed system microwave digestion vessel. An oxidizing fusion usually converts selenium into Se(VI) rather than Se(IV). 

Many methods for the oxidative cyclization of 2-aminophenones to 2,1-benzisoxazoles have been reported and these were extensively discussed by Wiinsch and Boulton (67AHC(8)277). An illustrative reaction is the treatment of an aminophenone with hydrogen peroxide or potassium persulfate to produce 2,1-benzisoxazoles (Scheme 181) (64USP3261870). 

Diaminoazobenzene was reported by Nietzki to have been prepared by diazotizing -nitroaniline and coupling the product with aniline. The resulting 4-nitrodiazoaminobenzene is rearranged and the nitro group reduced. The submitters tried several times to carry out this procedure but were unsuccessful. 4,4 -Diaminoazobenzene has been prepared by the oxidation of -nitroaniline with potassium persulfate followed by the reduction of the nitro groups. ... 

The decarboxylation reactions of fluonnated carboxylic acids are similar to those of their nonfluonnated counterparts, but predictably many exceptions exist The oxidation of the potassium salts of perfluoro acids with potassium persulfate leads to decarboxylation and coupling [93] (equation 59)... 

The oxidizing agent is prepared in a 500-ml flask equipped with a magnetic stirrer and cooled in an ice bath as follows In the flask are placed 60 ml of concentrated sulfuric acid and 20 ml of water, and the solution is cooled to 10°. Potassium persulfate (42 g, 0.15 mole) is added slowly to the stirred solution while maintaining the temperature below 10°. The solution is diluted with an additional 65 ml of water maintaining the temperature below 15°. The solution is now cooled to about 7° and 0.08 mole of the ketone is added over 40 minutes. After the addition has been completed, the solution is allowed to come to room temperature and stirring is continued for 20 hours. The solution is diluted carefully with 150 ml of water and extracted twice with 75-ml portions of ether. The ether is washed with sodium bicarbonate solution, followed by water, and the ethereal solution is dried. Removal of the solvent, followed by fractional distillation, affords the product ester. 

In a recently published paper6, on the investigation of AN copolymerization with the quartemary salt of l,2-dimethyl-5-vinylpyridinium sulfate (DMVPS) in dimethyl sulfoxide (DMSO) with 2,2 -azoisobutyronitrile as initiator, and in aqueous medium in the presence of the potassium persulfate/sodium metabisulfite oxidation-reduction system at 60 °C, the authors found the reactivity of the monomers, especially that of MVPS (methylvinylpyridin sulfate) to depend significantly on the polarity of the medium. 

The oxidation of D-glucose with potassium persulfate occurs very slowly at room temperature the optimum temperature is 40°, but the yield of osone is very small.38... 

Some years later, Miller and others (1996) described a modified TEAC assay that is able to determine the antioxidant activity of carotenoids. In the improved version, ABTS,+, the oxidant, is generated by oxidation of 2,2 -azinobis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS2 ) with manganese dioxide. A similar approach was described by Re and others (1999) in which ABTS was oxidized with potassium persulfate (Fig. 10.2), this version of the TEAC assay is applicable to both water soluble and lipophilic antioxidants (Re and others 1999 Pellegrini and others 1999). 

Hannaker and Buchanan [82] used a method based on wet oxidation with potassium persulfate [83] for the determination of dissolved organic content in concentrated brines following the removal of inorganic carbonates with phosphoric acid. The method involves wet oxidation with potassium persulfate at 130 °C followed by a hot copper oxidation and gravimetric measurement of the carbon dioxide produced. The technique overcomes difficulties of calibration curvature, catalytic clogging, and instrument fouling often encountered with instrumental methods. 

An example of an automated colorimetric method, oxidation by ultraviolet irradiation for the determination of dissolved organic carbon in the presence of potassium persulfate [ 87], is that of Schreurs [86 ]. The method uses a Technicon analyser to measure dissolved organic carbon, is fast and precise, and may be used to measure dissolved organic carbon in both seawater and fresh water over the range 0.1 -10 mg C per litre. 

An alternative method for the determination of particulate organic carbon in marine sediments is based on oxidation with potassium persulfate followed by measurement of carbon dioxide by a Carlo Erba non-dispersive infrared analyser [152,153]. This procedure has been applied to estuarine and high-carbonate oceanic sediments, and results compared with those obtained by a high-temperature combustion method. 

Potassium persulfate, reagent for oxidation of o-iodobenzoic acid, 46, 107... 

Nitrites, inorganic Nitrogen oxides (NOx) Oxygen Peracetic acid Perchloric acid solutions Potassium bromate Potassium chlorate Potassium dichloro-s-triazinetrione (potassium dichloroisocyanurate) Potassium dichromate Potassium percarbonate Potassium perchlorate Potassium permanganate Potassium peroxide Potassium persulfate Potassium superoxide n-Propyl nitrate... 

Wet oxidation Several types of liquid-phase oxidizing agents, such as nitric acid, acidic potassium permanganate, acidic potassium dichromate, dichromate permanganate, hydrogen peroxide, ammonium bicarbonate and potassium persulfate, have... 

Mercury is most accurately determined by the cold vapor atomic absorption spectroscopic method. The instrument is set at the wavelength 253.7 nm. The metal, its salts and organic derivatives in aqueous solution can be measured by this method. The solution or the solid compounds are digested with nitric acid to convert into water-soluble mercury(ll) nitrate, followed by treatment with potassium permanganate and potassium persulfate under careful heating. The excess oxidants in the solution are reduced with NaCl-hydroxylamine sulfate. The solution is treated with stannous chloride and aerated. The cold Hg vapor volatdizes into the absorption cell where absorbance is measured. 

Silver(ll) oxide is prepared by reacting silver nitrate with potassium persulfate in the presence of a base. 

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