Showing papers on "Potassium hydroxide published in 1998"

Investigation of alkaline hydrolysis of polyethylene terephthalate by differential scanning calorimetry and thermogravimetric analysis

Abstract: The hydrolytic depolymerization of polyethylene terephthalate (PET) with alkaline hydroxides was investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The reactions of the mixtures were conducted in their solid states under nitrogen atmosphere. The experimental results showed that potassium hydroxide possessed the hydrolytic activity of depolymerizing PET into small molecules such as ethylene glycol; in contrast, sodium hydroxide did not. The production rate of ethylene glycol was enhanced by increasing charge ratio of potassium hydroxide to PET. The presence of water facilitated the alkaline hydrolysis of PET; however, the presence of metal acetates decreased the hydrolysis rate. The activation energy for alkaline hydrolysis of PET determined by the thermograms was in good agreement with the value obtained from the experiments in a batch reactor. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 1939–1945, 1998

Investigations of a new family of alkaline-fluoride-carbonate electrolytes for zinc/nickel oxide cells

Abstract: A new family of reduced-alkalinity electrolytes containing fluoride and carbonate anions significantly extends the cycle-life performance of zinc/nickel oxide cells. Various compositions of this family of electrolytes, with a range of KOH concentrations from 2 to 6.9 M, were characterized for zinc/nickel oxide cell cycle-life and power performance, and their conductivities were measured for a range of operating temperatures. The optimum composition for this type of electrolyte based on these criteria was determined to be 3.2--4.5 M KOH with 2 M KF, 2 M K{sub 2}CO{sub 3}, 0.5 M, LiF (suspension), and saturated ZnO. The cycle-life performance for 1.4 Ah sealed cells with the optimum electrolytes is 425--460 cycles to 80% of initial capacity, compared to 75--100 cycles for the conventional highly alkaline electrolyte, 6.8 M:1 M KOH-LiOH, saturated ZnO, a factor of 5 improvement.

Method for separating sterols from tall oil

Abstract: A method is set forth for separating a sterol or sterol ester from crude tall oil comprising fractionating the crude tall oil into a residue fraction and a volatile fraction, wherein the temperature of the residue fraction does not exceed about 290° C., and wherein the residue fraction includes the sterol or sterol ester. By application of this method, which can be implemented in existing fractionating equipment or in specially designed pitch collecting apparatuses disclosed herein, the yield of sterols can exceed 50% with respect to the sterols present in crude tall oil. A method is also provided for separating unsaponifiable material from a tall oil stream comprising saponifying the stream with a mixture of sodium hydroxide and potassium hydroxide to form sodium and potassium salts of fatty acids, rosin acids, or both; evaporating the unsaponifiable material; and acidulating the unevaporated sodium and potassium salts.

Alkaline cell with semisolid cathode

Abstract: An alkaline cell is disclosed having a cathode comprising manganese dioxide wherein the cathode is a semisolid during discharge of the cell. The cell has an anode comprising zinc and an electrolyte comprising potassium hydroxide. The semisolid cathode comprising manganese dioxide may be in the form of a putty or paste. The semisolid cathode reduces cathode polarization effects and results in increased manganese dioxide utilization (Amp-hr/g), particularly at high current drain, between about 0.5 and 2 Amp. The porosity of the cathode is between about 45% and 70%, and the volume ratio of electrolyte solution in the cathode to the solids in the cathode is at a value between about 0.7 and 2.3.

In situ gas scrubbing method and system for odor and corrosion control in wastewater collection systems

Abstract: A process and system for reducing the concentration of odorous contaminants, primarily hydrogen sulfide, in the vapor spaces of sewage handling and treatment systems, primarily the vapor spaces of sewage trunk lines, by injecting a fine spray, mist or fog of a dilute solution of hydrogen peroxide and a base selected from a group consisting of sodium hydroxide, potassium hydroxide, ammonium hydroxide and sodium carbonate to mix intimately with the vapor flow. The peroxide and base solutions may be pre-mixed and diluted with water and injected through atomizing nozzles utilizing compressed air as an atomizing fluid. The system may also provide for separate storage of the peroxide and base solutions, mixing of the peroxide and base solutions with dilution water with in-line mixing devices and direct injection with or without compressed air atomization into the vapor space. Sewage trunk lines, in particular, are treated at a substantial distance upstream of the sewage treatment facility to allow for adequate reaction time to reduce the concentration of the contaminant and reduce loading and corrosion on sewage treatment and foul air handling and scrubbing equipment.

Additives for rechargeable alkaline manganese dioxide cells

Abstract: Rechargeable galvanic cells are disclosed which comprise a manganese dioxide cathode, a zinc anode and a potassium hydroxide electrolyte wherein the cathode includes additive compounds to increase the cumulative discharge capacity of the cell thereby increasing its cycle life. The additives consist of a) barium or strontium compounds, and mixtures thereof, and b) titanium, lanthanum, yttrium, cerium, zinc, calcium, tin or magnesium compounds, and mixtures thereof.

Synthesis and mesomorphic properties of some cyclohex-2-en-1-one derivatives

Abstract: Mesomorphic properties of cyclohex-2-en-1-ones belonging to 14 different chemical structural types are compared and discussed. They were prepared by condensation of Mannich salts with 2-substituted acetoacetates or benzyl methyl ketones or acetylacetone in the presence of potassium hydroxide.

Polymerization of 1-Methyl-2,5-bis[1-(4-phenylurazolyl)] pyrrole dianion with alkyldihalides

Abstract: 1-Methyl-2,5-bis[1-(4-phenylurazolyl)] pyrrole was prepared from the reaction of 4-phenyl-1,2,4-triazoline-3,5-dione with N-methylpyrrole in methylene chloride solution. This compound was converted to its potassium dianion salt upon reaction with potassium hydroxide in absolute ethanol. The reaction of this dianion salt with excess methyl iodide in dimethyl sulphoxide gave the methylated adduct in high yield. Polymerizations of this dianion salt with 1,2-dibromoethane, 1,2-diiodoethane and 1,4-diiodobuthane were performed in dimethyl sulphoxide and led to the formation of new polymers. Some structural characterization and physical properties of these novel polymers are reported.

Method for improved metal oxide bonding of optical elements

Abstract: A method of preparing a supporting substrate of an optical subassembly for metal-oxide bonding an optical element to the substrate. The method includes providing a supporting substrate including a metalized region for metal-oxide bonding an optical element to the substrate and rinsing the substrate in a potassium hydroxide solution. The potassium hydroxide solution removes any excess metal oxide or other contaminants from the surface of the metalized region.

Production of zirconia-ceria composition

Abstract: PROBLEM TO BE SOLVED: To efficiently produce a zirconia-ceria compsn. excellent in heat resistance by mixing crystalline cerium sulfate with a soln. contg. zirconium ions and then adding a base. SOLUTION: A dispersion prepd. by dispersing 20-30 pts.wt. crystalline cerium sulfate of 1-30 μm average particle diameter in 100 pts.wt. medium such as water is mixed with a soln. having 10-20 wt.% concn. of a zirconium salt such as zirconium nitrate in a weight ratio of 1:0.25 to 1:1.2 (expressed in terms of ceria to zirconia), a third component such as lanthanum nitrate is, if necessary, added by 1-20 wt.% (expressed in terms of oxide) and a base such as an aq. soln. of potassium hydroxide having 5-25 wt.% concn. is added to form zirconium hydroxide on the crystalline cerium sulfate. This product is calcined at ≥400°C in the air or in an oxidizing atmosphere to obtain the objective zirconia-ceria compsn. having <80 wt.% ceria content, <5 wt.% sulfuric acid radical content, ≥1.0 mmol/g hydrogen consumption, ≥130 m 2 /g specific surface area at 400°C and ≥15 m 2 /g specific surface area at 1,000°C. COPYRIGHT: (C)1999,JPO

Method for obtaining LSX zeolite bodies

Abstract: A process for the production of faujasite X agglomerates containing at least 95% of faujasite LSX, that is to say with an Si/Al ratio equal to 1, constituting the active adsorbent The agglomerate is formed from zeolite LSX and from a binder which can be converted to zeolite, the conversion of which to active zeolite is obtained by conversion to zeolite in a sodium hydroxide/potassium hydroxide or sodium hydroxide liquor

Process for the recovery of precious metals

Abstract: The invention relates to a method for detaching precious metal layers from a correspondingly coated material by dissolving the precious metals in a salt-containing alkali cyanide solution containing oxidizing agents. According to the invention the alkali cyanide solution continuously flows around the material positioned in a dissolution unit (22), preferably contains at least an alkali sulfate, an alkali metaborate and/or a nitroaromatic compound and for obtaining and/or regenerating the oxidizing agent is electrolytically oxidized in a closed circuit in an electrolytic cell (10). The method provided for by the invention there requires minimal quantities of chemicals, which results in correspondingly low recycling costs. If a nitroaromatic compound is used the oxidized solution is stable to such a degree that the dissolution process in the dissolution unit (22) and the oxidizing process in the electrolytic cell (10) can be carried out independently of each other. The precious metals dissolved in the alkali cyanide solution, such as gold, silver, palladium or such like, and/or impurities are preferably separated out electrolytically in the cathode compartment (28) of a further electrolytic cell (26) which chamber is separated from the corresponding anode compartment (30), which is filled with a powerful electrolyte, for example a 10 % potassium hydroxide solution, by a cation exchange membrane (32). Said membrane is preferably coated with a precious metal, notably gold, since this permits extremely high degrees of purity of up to 99 % during separation.

Synthesis and characterization of a c-functionalized chelating carboranyl ligand and its chromium(iii) complex

Abstract: The reaction of l,2-dicarba-o-carborane with two equivalents of t-butyllihum in THF followed by the addition of 2chloromethylpyndinc produced 1-(-CH2C5H4N)-1,2-C2B10H11, (1), in 65% yield Cage degradation of (1) using potassium hydroxide in 95% ethanol followed by the addition of cesium iodide produced [7-(CH2C5H4N)-7,8- C2R9H11],Cs∗ (2) Reaction of compound (2) with NaH, followed by 1 equiv of anhydrous chromium(III) chloride afforded the chromacarborane [7-(CH2C5H4N)-7,8-C2B9H10CrCI], (3) Compound (3) was characterized by elemental analyses, IR and mass spectra Compounds (1) and (2) were characterized by elemental analyses, IR, and NMR In addition, compound (1) was also characterized by single crystal X-ray diffraction

Alkaline organic photoresist stripper

Abstract: A stripper for removing photoresist or solder masks has a composition of 30-80% by weight of a propylene glycol ether; 10-60% by weight of a pyrrolidone; 0.1-5% by weight of potassium hydroxide; 0.1-10% by weight of a surfactant; 0-20% by weight 1,3-butanediol; 0-10% by weight 2-(2-aminoethoxy) ethanol; and a water content of <1%.

Method for repairing alternating phase shifting masks

Abstract: A method of repairing quartz bump defects on an alternating phase shifting template such as a mask or reticle that includes the steps of locating a defect by either SEM scanning or low energy FIB scanning; directing a FIB at the bump defect, and irradiating the bump detect with high energy ions from the FIB. After the bump has been thoroughly stained with ions, the template is exposed to a strongly basic solution to remove the stained bump. Suitable bases include sodium hydroxide, potassium hydroxide, ammonium hydroxide, to tetramethyl ammonium hydroxide, and the like. According to this method, a quartz bump defect is removed with high precision and less damage to the substrate.

Stabilized liquid lime dispersion for sewage treatment

Abstract: A stabilized lime slurry for treatment of biological solids in sewage. The composition preferably includes 30-36 % calcium hydroxide, 10-16 % potassium hydroxide, 2-4 % potassium chloride, 2-4 % magnesium hydroxide, all on a dry basis, and the balance in water. This composition raises the pH rapidly for destroying pathogens, is sufficiently concentrated for economically feasible transportation, and reduces the cost, difficulties and dangers of treating sewage with a lime based composition while providing a resulting product from the sewage treatment process which can be spread upon agricultural soil in a manner which improves soil fertility without introducing undesirable or contaminating materials into the soil.

Storage stabilization of compound having oxetane ring

Abstract: PROBLEM TO BE SOLVED: To provide a method for stabilizing the storage of a compound having an oxetane ring useful as a monomer capable of conducting ring-opening polymerization SOLUTION: The characteristic of this method for stabilizing the storage of a compound having an oxetane ring is to add a basic compound A basic inorganic compound such as an alkali metal hydroxide and a basic organic compound such as an amine can be used as the basic compound of the method Lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogencarbonate, magnesium hydroxide, calcium hydroxide and potassium carbonate, or the like, are cited as the basic inorganic compound Among them, the alkali metal hydroxide such as the lithium hydroxide, sodium hydroxide and potassium hydroxide are preferred from the aspects of solubility in the oxetane compound

Production of active material of positive electrode for secondary battery

Abstract: PROBLEM TO BE SOLVED: To provide a method for producing an active material of a positive electrode for a nonaqueous electrolyte secondary battery, especially a lithium ion secondary battery, excellent in durability in cycling and hardly deteriorating charge and discharge characteristics. SOLUTION: At least one of a hydroxide, an oxyhydroxide or an oxide of a nonmanganese metallic element selected from aluminum, magnesium, vanadium, chromium, iron, cobalt, nickel and zinc is made to adhere to the surface of a powder comprising a lithium manganese compound oxide represented by the formula Lix My Mn2-x Oz [M denotes a nonmanganese element; (x), (y) and (z) denote each a number within the range of 0.5<(x)<=1.2; 0<(y)<=0.2 and 3.8<(z)<=4.2] and the resultant powder is then heated. The adhesion of at least one of the hydroxide, oxyhydroxide or oxide is carried out by reacting an aqueous solution containing the salt of the nonmangenese metallic element with an alkali consisting essentially of sodium hydroxide or potassium hydroxide or a salt thereof with a weak acid.

Evaluation and Improvement of Transesterification Methods of Triglycerides

Abstract: The causes responsible for the low reproducibility of the gas chromatographic method used to analyze fatty acid methyl esters, derived from the transesterification of triglycerides in n-hexane by means of methanol potassium hydroxide, were identified and eliminated. Partition coefficients (Kd) of short-chain fatty acid methyl esters between n-hexane and methanol were determined. These results indicate that even under the best experimental conditions, a substantial portion of these compounds are transferred in the methanol phase and therefore are not analyzed. Accurate results, to within 2%, were obtained by rigorously controlling the volume of the reagents and introducing appropriate correction factors. The accuracy of the results, reported as a percentage by weight, did not depend on the completeness of the transesterification reaction. In the analysis of fatty acids as butyl esters, a measurable quantity of butyric ester was lost during the washing phase with water. By contract, butyric acid pe...

Detached plume abatement method

Abstract: A method is provided for abating acidic contaminants, such as sulfur dioxide and hydrogen chloride, in exhaust gases while minimizing the formation of visible plumes of ammonium salts proximate to the outlet of the exhaust stack by injecting a spray of an alkaline liquid, such as sodium hydroxide or potassium hydroxide, into the contaminated exhaust gases wherein the pH of the alkaline liquid is high enough, i.e. greater than a pH of about 11, so that the acidic contaminants preferentially react with the alkaline liquid rather than the ammonia in the gases, thereby minimizing formation of visible plumes of ammonium salts.

Method for regenerating arsenic adsorbent

Abstract: PROBLEM TO BE SOLVED: To efficiently desorb arsenic adsorbed on an arsenic adsorbent to such a degree that the adsorbent can be reused by carrying out treatment with an alkali and an oxidizing agent. SOLUTION: A used arsenic adsorbent containing hydrous oxide of a rare earth element and/or hydrous oxide of zirconium is regenerated by treatment with an alkali and an oxidizing agent, preferably an oxidizing agent which does not deteriorate the structure and performance of the adsorbent. Hydrogen peroxide or sodium hypochlorite is particularly preferably used as the oxidizing agent. The oxidizing agent may be used alone before alkali treatment or may be used as a mixture with the alkali regenerating agent. When the oxidizing agent is used alone before alkali treatment, pH in reaction may be in any of acidic and alkaline regions. Hydroxide of an alkali metal may be used as the alkali agent and sodium hydroxide or potassium hydroxide is preferably used because a high desorption rate is attained.

Method of producing of protective coatings on aluminum and its alloys

Abstract: FIELD: protection of articles from abrasive wear and high-temperature corrosion; applicable in aviation, mechanical engineering, automotive and other industries. SUBSTANCE: the offered method is realized by microarc oxidation with voltage of coating formation of 160-170 V and current density of 0.9-1.2 A/sq.cm in electrolyte based on sodium hexafluoroaluminate with electrolyte pH 9.8-10.2. Electrolyte contains the following components, g/l: sodium hexafluoroaluminate 2.0-12.0; potassium tartrate 5.0-10.0; sodium fluoride 0.5-2.0; potassium hydroxide 0.5-0.6. Formation in composition of coating of glass phase based on aluminum oxide modified with fluorine allows production of protective anticorrosive coatings possessing high microhardness and heat resistance. EFFECT: higher efficiency. 2 tbll

Method for repairing phase shifting masks

Abstract: A method of repairing opaque defects on a phase shifting template such as a mask or reticle that includes the steps of directing a focused ion beam (FIB) to scan a small region including an opaque defect. By monitoring a change in the intensity of a secondary signal, the end of the etching process is detected, and the template is exposed to a strongly basic solution to remove ion stains and repair residue produced by the FIB sputtering process. Suitable bases include sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetramethyl ammonium hydroxide, and the like. According to this method, an opaque defect is removed with high accuracy of edge placement and high quality of geometry reconstruction, and the phase shifting amount and the transmission of the opaque defect area are adjusted to their proper levels with high precision.

Corrosion Fatigue Crack Growth Behavior of Titanium Alloys in Aqueous Solutions

Abstract: The corrosion fatigue crack growth (FCG) behavior, the effect of applied potential on corrosion FCG rates, and the fracture surfaces of VT20 (near-α) and TS6 (near-β) titanium alloys were studied. Environments were aqueous solutions of sodium chloride (NaCl), sodium hydroxide (NaOH), potassium hydroxide (KOH), ferric chloride (FeCl3), and chromic acid (H2CrO4) with and without NaCl. Depending upon solution composition, corrosion FCG rates were found to be higher or lower than those in air. Cathodic polarization retarded the corrosion FCG, while anodic polarization accelerated insignificantly or almost did not influence it in most of the solutions investigated. However, cathodic polarization accelerated corrosion FCG in 0.6 M FeCl3 and 0.5 M to 2 M H2CrO4 + 0.01 M to 0.1 M NaCl solutions by a dozen times when the maximum stress intensity (Kmax) exceeded certain critical values. When Kmax was lower than the critical values, the same cathodic polarization (with all other conditions being equal) reta...

Method of manufacturing gelatin

Abstract: The present invention is a process for the manufacture of gelatin which includes providing a collagen containing material and demineralizing the collagen containing material to produce ossein. The ossein is added to a water solution containing at least 3% sodium hydroxide or potassium hydroxide and at least 3% sodium sulfate for a time sufficient to form a reacted slurry. The reacted slurry is heated to a temperature of at least 45° C. for a time sufficient to solubilize the ossein thereby producing a solution containing gelatin. The pH of the solution containing gelatin is raised to greater than 9.8. The pH of the solution containing gelatin is reduced with a sulfate salt of a divalent or trivalent metal to a neutral pH (between 7.0 and 8.0). The pH of the gelatin solution is then lowered to between 5.0 and 6.0 and a polymeric flocculant is added to the gelatin solution in an amount of less than 0.1% based on the dry weight of the gelatin to form a floc and the floc is removed. The resulting gelatin is filtered and desalted.

Catalyst composition for polymerizing propylene oxide

Abstract: PROBLEM TO BE SOLVED: To obtain the subject composition capable of producing poly(propylene oxide) whose mol.wt. can be controlled and which has a relatively narrow mol.wt. distribution width and hydroxyl groups at both the molecular ends by mixing a crown ether compound with an alkali metal alkoxide, etc. SOLUTION: This catalyst composition for polymerizing propylene oxide comprises (A) a crown ether compound, preferably 18-crown 5, benzo 18-crown 6, dibenzo 18-crown 6, etc., (B) an alkali metal alkoxide such as potassium t-butoxide or an alkali metal hydroxide such as potassium hydroxide, and (C) an organic Lewis acid, preferably methyl aluminum 2,6-di-t-butyl-4- methylphenoxide, methyl aluminum 2,2'-methylenebis(5-t-butyl-4- methylphenoxide), etc. The component A is preferably contained in an amount of >=1 mole per mole of the component B.