Showing papers on "Potassium hydroxide published in 1989"

Solubility and Aging of Calcium Silicate Hydrates in Alkaline Solutions at 25°C

Abstract: Calcium silicate hydrate (C-S-H) gels are the principal bonding material in portland cement. Their solubility properties have been described, enabling pH and solubilities to be predicted. However, the gels also interact with other components of cements, notably alkalis. C-S-H has been prepared from lime and silicic acid in solutions of sodium hydroxide or potassium hydroxide and by the hydration of tricalcium silicate (C3S) in sodium hydroxide solutions. Analyses of aqueous phases in equilibrium with 85 gels show that the aqueous calcium and silicon concentrations fit smooth curves over the range of increasing sodium concentrations. Where anomalous data occur, they correspond to solids with low lime contents: such gels are tentatively assumed to fall into a region where the presence of another gel phase influences the aqueous composition. Dimensional changes have been observed in the hydration products of C3S as a function of alkali content and these may be relevant to the alkali-silica reaction. The significance of this and other data is discussed with reference to real cement systems.

Production of high quality activated carbon

Abstract: The invention relates to a method of producing activated carbon with a large surface area and a low sulfur content Coconut shell char, as a carbonaceous material, is mixed with granular potassium hydroxide hydrate with a water content of 2 to 25 weight %, as an activator, in a weight ratio of 1:2 through 1:6 and the mixture is heat-treated at a temperature necessary for activation

Synthesis of L-[5-11C]ornithine.

Abstract: No-carrier-added L-[5-11C]ornithine was synthesized in 25–40% radiochemical yield in a synthesis time of 50 min (EOB) and a specific activity >2.1 Ci/umol by the displacement reaction of potassium [11C]cyanide with the functionally protected y-bromohomoserine followed by selective reduction of the [11C]nitrile with cobalt chloride-sodium borohydride complex, deprotection with 6M HCl(aq), and purification by HPLC. During the course of these studies it was found that cyanide ion is generated from acetonitrile in the presence of potassium hydroxide and kryptofix 222.

Production of shikonin

Abstract: PURPOSE: To obtain shikonin having high purity and useful as a raw material for pharmacenticals, etc., in high yield by adding an alkaline aqueous solution to an extract of shikonin ester extracted with an organic solvent, hydrolyzing the ester without separating the aqueous phase from the organic phase and separating the objective compound from the aqueous phase. CONSTITUTION: Natural SHIKON (root of Lithospermum erythrorhizon) or callus of Lithospermum erythrorhizon prepared by tissue culture is extracted by using an organic solvent as an extraction solvent. The extract liquid containing a shikonin ester of formula (R is alkyl) is added with an alkaline aqueous solution such as aqueous solution of potassium hydroxide, sodium hydroxide, etc., and the ester is hydrolyzed in the presence of the extraction solvent without separating the aqueous phase from the organic phase. After the hydrolysis, the aqueous phase is separated from the mixture and shikonin is separated from the aqueous phase to obtain shikonin having bactericidal action, exhibiting excellent effect against various dermatic diseases and useful also as a dye, etc. The compound can be produced in high purity and efficiency while suppressing the formation of hydrolysis by-product. COPYRIGHT: (C)1991,JPO&Japio

Process for the preparation of polyether polyols with reduced unsaturation

Abstract: Polyether polyols having an equivalent weight of from 200 to 4000 are prepared by the process of this invention. The process uses barium- or strontium-containing alkoxylation catalysts to provide products with reduced unsaturation in comparison to similar products produced with potassium hydroxide catalysis. In a preferred embodiment of the process, water is added during the reaction of the monoepoxy compound with the initiator. The quantity of water added is one percent or less by weight of the total weight of monoepoxy compound to be reacted with the initiator.

Transesterification of triglycerides

Abstract: A process for converting liquid triglycerides into solid triglycerides by means of random transesterifications achieved through the use of catalytically active combinations comprising the reaction product of mixtures of dihydroxy and trihydroxy alcohols with mixtures of alkali metal hydroxides, and with ketones. The catalytically active materials can be employed in directed transesterifications in which the transesterification reaction mixture is subjected to a series of heating and cooling cycles during which higher melting fats are formed and precipitated from solution, causing an equilibrium shift that results in the formation and precipitation of still additional higher melting fats. An especially desirable catalytically active combination comprises the reaction product of 1, 2 propanediol, 1,3 propanediol and glycerol, with sodium hydroxide and potassium hydroxide, and in a preferred embodiment, the reaction product is combined with acetone to form the catalytically active combination.

Synthesis and study of 5a,6-dihydro-12H-indolo[2,1-b][1,3]-benzoxazines

Abstract: Reaction of 2,3,3-trimethyl-, 2,3,3,5- and 2,3,3,7-tetramethyl-3H-indoles with 4-nitro-2-chloromethylphenol has given the 5a,6-dihydro-12H-indolo-[2,1-b][1,3]-benzoxazines, which have been examined for ring-chain interconversion by NMR spectroscopy. Treatment of 5a,6-dihydro-12H-indolo[2,1-b][1,3]benzoxazines with either perchloric acid or potassium hydroxide results in opening of the dihydrooxazine ring with the formation of indole derivatives.

Possible mechanisms for the revival of glutaraldehyde-treated spores of Bacillus subtilis NCTC 8236.

Abstract: Spores of Bacillus subtilis NCTC 8236 were exposed to 2% alkaline glutaraldehyde and subsequently subjected to various treatments in an attempt to revive injured spores. Treatment with alkali (sodium or potassium hydroxide or, to a lesser extent, sodium bicarbonate) proved to be most successful. Some revival was achieved after thermal treatment. No revival was obtained with lysozyme or with various types of coat-removing agents. Experiments designed to distinguish between germination and outgrowth in the revival process established that sodium hydroxide (optimum concentration, 20 mmol/l) added to glutaraldehyde-treated spores increased the potential for germination. In contrast, spores which had been allowed to germinate before exposure to low concentrations of glutaraldehyde and then to sodium hydroxide were inhibited at the outgrowth phase to a much greater extent than germinated spores treated with the dialdehyde without subsequent alkali exposure. The results overall are discussed in terms of the possible mechanism and site of action of glutaraldehyde and the practical implications and significance of its use as a sporicide.

Method of treating arthritis

Abstract: A method of treating skin disorders, inflamatory conditions and certain internal infections and disorders by administering, either externally by topical application or internally through oral ingestion, an effective amount of a mixture of mineral compounds in appropriate parts by weight of aluminum oxide hydrate, iron, magnesium oxide, silicon dioxide, sodium hydroxide and potassium hydroxide, along with trace amounts of copper, zinc, and calcium, with the balance of the mixture comprising ammonium sulfate or, in the case of topically applied formulations, a pharmaceutically acceptable carrier or diluent.

Process for the preparation of 2-(4-chlorophenylethyl)-2-tert.-butyl-oxirane

Abstract: A process for making the known fungicide intermediate 2-(4-chlorophenyl ethyl)-2-tert.-butyloxirane of the formula ##STR1## comprising (a) mixing a solution of trimethylsulphonium bromide of the formula (CH3)3 S.sup.⊕ Br.sup.⊖ (II) in a methanol/toluene mixture with preheated toluene and simultaneously distilling off a methanol/toluene mixture at a temperature between 65° and 110° C. until a suspension having a solids content between 10 and 70% by weight is formed, and (b) reacting the suspension of trimethylsulphonium bromide in toluene thus obtained with 1-(4-chlorophenyl)-4,4-dimethylpentan-3-one of the formula ##STR2## in the presence of solid potassium hydroxide, diethylene glycol and water at a temperature between 20° and 120° C., the amounts of the reaction components being such that per mole of 1-(4-chlorophenyl)-4,4-dimethylpentan-3-one of the formula (III) there are present between 1 and 2 moles of trimethylsulphonium bromide of the formula (II), between 2 and 3 moles of solid potassium hydroxide and also between 0.1 and 10% by weight of diethylene glycol and between 0.5 and 12% by weight of water, relative to 1-(4-chlorophenyl)-4,4-dimethylpentan-3-one of the formula (III).

Opacifying kaolin pigments and process for making same by reacting with sodium hydroxide in water

Abstract: An opacifying pigment with enhanced light scattering properties for use as a paper coating or filler material is produced by reacting kaolin in the presence of water with sodium hydroxide or potassium hydroxide at a temperature in excess of 60° C. The kaolin is reacted with the hydroxide in a concentration to produce a molality of at least 0.1.

Ion Exchange in Countercurrent Electrolysis in a Porous Membrane

Abstract: In many sepration processes for electrolytes the economy of the process could be improved if ion exchange could be carried out simultaneously with the separation without additional stages; i.e., when, for instance, separating potassium chloride from a mixture of sodium and potassium chlorides, the anion could be replaced by the hydroxyl ion, thus producing, instead of potassium chloride, more valuable potassium hydroxide. In fact, in the separation of cations an often desired ion-exchange reaction is the abovbe-mentioned replacement of some anion by the hydroxyl inon.

Ranking corrosion efficiency: a Latin square study on rat lung microvascular corrosion casts.

Abstract: Scanning electron microscopy of corrosion casts is an important tool for the study of microvascular structure but few systematic studies on methods of specimen preparation have been reported. This study sought to determine the relative importance of factors involved in corrosion. It compared potassium hydroxide, sodium hydroxide and water as major corrosive agents. It tested the size of the tissue sample, and the use of prealkali autolysis, detergent, and proteolytic enzymes in a Latin square designed study. The main findings were that sodium and potassium hydroxide were better than water (P less than 0.0001) and the longer the corrosion time the better corroded the samples were (P less than 0.0001). Although not a controlled factor, higher room temperature was also associated with better corrosion. The use of proteolytic enzymes, detergent, and warm tap water alone before the alkali treatment did not significantly improve the corrosion in this study, although this does not preclude an effect with another experimental design.

A modified synthesis of 4-chromanones

Abstract: Problems in the synthesis of 4-chromanones by condensation of 2-hydroxyacetophenones with formaldehyde can be avoided by the isolation of the Mannich base hydrochlorides and cyclization by titration with potassium hydroxide.

Large-Scale Preparation of Potassium Hydroxide-Modified Silica Gel Adsorbent

Abstract: A large-scale method, using custom-made apparatus, is described for making potassium hydroxide-modified silica gel. Batches as large as 2,3 kg can be made in 16 man-hours. A smaller-scale version of the method, requiring no specialized apparatus, is also described. The method can be used to integrate this adsorbent into many sample-enrichment procedures

Process for the preparation of alkyl or alkaline earth ferrates by the solid phase

Abstract: To prepare a potassium ferrate, 100 parts of ferrous sulphate heptahydrate and 68 parts of calcium hypochlorite with a chlorimeter value of 210 degrees are ground intimately to obtain a powder which passes through a 500- mu m mesh. This powder is formed into a layer onto which are scattered 100 parts of potassium hydroxide pellets containing 15% by weight of water. The whole is vibrated for 10 to 60 minutes, depending on atmospheric moisture content, while care is taken that the temperature does not exceed 40 C. The unreacted powder is removed by screening through a 1-mm mesh and the pellets are stoved at 120 C for 12 hours. The pellets are washed with methyl alcohol to remove most of the remaining potassium hydroxide and potassium chloride and carbonate as well as calcium chloride. The ferrate obtained, purple in colour, is stable in a closed vessel.

Production of fluorocarbonsulfonic acid

Abstract: PURPOSE:To obtain a large amount of the titled compound by a complete circulation system by a simple device and by simple operation, by bringing a fluorocarbonsulfonic acid fluoride into contact with a solution of potassium hydroxide in such a way that the surface area of the solution based on the amount of gas is enlarged. CONSTITUTION:A fluorocarbonsulfonic acid fluoride RfSO2F (Rf is 1-3C saturated or unsaturated perfluoroalkyl) is brought into contact with a solution of potassium hydroxide (absorbing solution) at ), especially <=0.15 per unit gas-liquid contact area at <=room temperature, especially 60-90 deg.C, absorbed and hydrolyzed. Then potassium hydroxide is added or the system is concentrated and cooled. Potassium salt (RfSO3K) is precipitated, separated and decomposed with an acid to give the aimed compound (RfSO3H). The residual solution after separating the potassium salt is incorporated with a hydroxide of an alkali (earth) metal, the precipitated fluoride is removed, the dissipated amount of potassium hydroxide is added to the solution, which is circulated as the absorbing solution.

Fast-dissolving, non-caking, food grade sodium tripoly-phosphate

Abstract: :FAST-DISSOLVING, NON-CAKING, FOOD GRADE SODIUMTRIPOLYPHOSPHATE A fast-dissolving, non-caking, food grade sodium tripolyphosphate is produced by spraying into a spray dryer an aqueous sodium orthophosphate feed liquor having an Na2O:P2Os ratio of from about 1.60 to about 1.67 containing potassium hydroxide or a soluble potassium salt in amounts to yield about 0.4% to 0.8%by weight potassium in the final product, heating the feed to at least 440°C to form sodium tripolyphos-phate, cooling the sodium tripolyphosphate and adding to it at least about 1% by weight moisture.

Production of bisnaphthalic acids

Abstract: PURPOSE: To obtain the subject compound useful as monomer for producing polyimide, etc., in high yield by using 4-halogenonaphthalic acids as raw materials, reacting in a specific aqueous solution containing base, formic acid and lower alcohol in the presence of a catalyst and dimerizing. CONSTITUTION: 4-halogenonaphthalic acids are reacted with heating at 90-120°C and dimerized in an alkaline aqueous solution containing base (preferably potassium hydroxide, etc.), formic acid and lower alcohol in the presence of a palladium catalyst to afford the compound expressed by the formula. 4- halogenonaphthalic acid, etc., is preferable as 4-halogenonaphthalic acids of raw material. Sodium formate, etc., is preferable as formic acid acting as reducing agent and the using amount of said acid is suitably 1-5 equiv. to the raw material. Methyl alcohol is preferable as lower alcohol and the using amount of said alcohol is 0.1-1 equiv. to the raw material. COPYRIGHT: (C)1991,JPO&Japio

Production of epoxide derivative

Abstract: PURPOSE:To obtain the title compound which is used as an intermediate of medicines readily in high yield, by allowing a specific compound to react with epichlorohydrin using a phase transfer catalyst, then adding a caustic alkali to complete the reaction. CONSTITUTION:The reaction of a compound of formula I (Ar is aryl) such as p-hydroxyphenylacetamide with epichlorohydrin of formula IV in the presence of a phase transfer catalyst of formula II (R' is 1-4C lower alkyl; R is benzyl, 1-8C lower alkyl; X is halogen, sulfate), when needed, in a solvent, preferably at 40-80 deg.C for 0.5-2hr to form a mixture of a compound of formula III and chlorohydrin of formula V. Then, a caustic alkali such as potassium hydroxide is added to the reaction mixture and heated at 70-80 deg.C for 1-3hr to complete the reaction whereby the subject compound of formula III is obtained, which is used as an intermediate of a drug having adrenergic blockade such as atenolol.

Carbonate formation and decomposition on KOH/Ag(111)

Abstract: Using x‐ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, temperature programmed desorption, and isotopic exchange, we have studied the formation of potassium hydroxide on Ag(111) and its conversion to carbonate. KOD forms from D2O and K dosed at 100 K when the surface is warmed to 300 K, and undergoes H/D exchange with H2O at low temperature. KOD(a) may be converted to adsorbed carbonate by exposure to CO2 at 300 K but not at 100 K.

Über die Produkte der Reaktion von Ethylbromid mit Kaliumhydroxid in wäßrig-alkoholischen Lösungen und den Verlauf dieser SN2-Reaktion

Abstract: About the Products of the Reaction of Ethyl Bromide and Potassium Hydroxide in Aqueous Alcoholic Solutions and the Progress of this SN2 Reaction In the textbooks of organic and general chemistry the reactions of ethyl bromide or methyl bromide with hydroxide ions in alcoholic or aqueous-alcoholic solutions are the main examples for the SN2 reaction mechanism first established by INGOLD and HUGHES in 1933–1935. It seems clear that the main product of the reaction between ethyl bromide and potassium hydroxide is ethanol apart from a small proportion of ethene in the competing elimination reaction. But the main product of this reaction in ethanolic or aqueous ethanolic solution is diethyl ether or in methanolic or aqueous methanolic solution methyl ethyl ether. Even in the case of using only water, potassium hydroxide and ethyl bromide one can gain 17% of diethyl ether. Kinetic investigations demonstrate that there is a real equilibrium between ethoxide and hydroxide ions in aqueous ethanolic solution. The equilibrium constant is near 0.5, that means that a mixture of ethanol and water contains a rather high amount of ethoxide ions if potassium hydroxide is dissolved in the solution. On the other hand, in the substitution reaction ethoxide ions react 2.5 times faster than OH⊖ at 20°C and 4.5 times faster at 100°C. Therefore, the main substitution reaction in aqueous ethanolic solution after formation of ethoxide ions according to the equilibrium is the reaction to diethyl ether according to

Errors in the measurement of extractable soil inorganic nitrogen caused by impurities in the extracting solution

Abstract: The potassium salts used as extracting solutions to determine soil inorganic nitrogen contain nitrogen impurities which could introduce a small error into the analysis. Ammonium nitrogen can be removed from the extracting solutions by raising the pH of the solution to pH 11.0 by the addition of 1 Molar potassium hydroxide and then boiling and stirring for a period of 15 minutes to expel all the ammonia. The pH can be readjusted to 6.0 with an appropriate dilute acid depending on the potassium salt being purified. As there is no simple method for the removal of nitrate it is suggested that the potassium salts are tested and a batch with a low level of nitrate selected for use where soil nitrate levels are expected to be low.

Aldol condensation of nitroparaffins

Abstract: A process for reacting nitroparaffins with formaldehyde in the presence of potassium hydroxide by aldol condensation which can be carried out continuously or discontinuously and on a large scale. This is achieved by mixing the nitroparaffin, aqueous aldehyde solution and potassium hydroxide in the absence of organic solvents and carrying out the reaction while maintaining the temperature between -5° and +20° C.

Process for producing potassium manganate

Abstract: Potassium manganate is produced by mixing finely ground manganese ore with a solution of potassium hydroxide (having a concentration of about 50% W/V) in a mole ratio KOH/MnO 2 between 2 and 3 The resulting suspension is fed continuously to an atomization dryer and then to a plate dryer

Surface treatment of molded article of liquid crystal polyester resin

Abstract: PURPOSE:To contrive to improve processing properties of surface of plating or coating, by adding an inorganic filler containing a specific element to a polyester to be subjected to melt processing to give a molded article of liquid crystal polyester resin and bringing the molded article into contact with an aqueous solution of an alkali (earth) metal hydroxide. CONSTITUTION:A polyester (aromatic polyester having preferably 20,000-25,000 weight- average molecular weight) which is capable of forming an anisotropic melt phase and is subjected to melt processing is blended with 5-80wt.%, preferably 20-70wt.% based on the total weight of the composition of an inorganic filler containing one or more elements of IIa, IIb, IIIa, IVa and Va groups of the periodic table and molded to give a molded article of liquid crystal polyester resin, which is brought into contact with an aqueous solution of an alkaline (earth) metal hydroxide (preferably potassium hydroxide) to give a molded article having surface characteristics suitable for surface decoration and adhesion of plating and coating. An inorganic filler containing a phosphate of an element of the group IIa of the periodic table is preferable for plating and an inorganic filler containing an oxide of an element of group IIIa for coating.

Chapter 9 Alkaline Flooding

Abstract: Publisher Summary This chapter discusses alkaline flooding. Alkaline waterflooding is an enhanced oil recovery process where the pH of the injection water is increased by the addition of relatively inexpensive alkaline agents, such as sodium carbonate, sodium silicate, sodium hydroxide, and potassium hydroxide, in an effort toward improving oil recovery. It was recognized as early as 1917 that the displacement of oil may be improved by introducing alkali into water. In the alkaline flooding process, the alkali reacts with the acidic constituents in the crude, leading to lower water-oil interfacial tension, emulsification of oil and water, and solubilization of rigid, interfacial films. The alkali may react with the reservoir rock, leading to wettability alteration. All these mechanisms potentially increase oil recovery. The alkaline flooding process is a relatively simple process as compared to other chemical floods, but is still sufficiently complex to warrant careful laboratory investigation and field trials before application. This chapter discusses the types of caustics used in alkaline flooding process. Entrapment of residual oil is discussed in the chapter. Displacement mechanisms in alkaline flooding are also presented in the chapter.