Showing papers on "Acetone published in 1974"

The thermal decomposition of calcium, sodium, silver and copper(II) acetates

Abstract: The thermal decomposition of the acetates of calcium, sodium, silver and copper(II) have been investigated using thermogravimetry and differential thermal analysis, together with analysis of the gaseous products formed during the decomposition process. The results indicate that the major organic product formed is either acetone or acetic acid, depending on whether the final solid product is the oxide or the metal.

Respiratory elimination of organic solvents in man

Abstract: Respiratory elimination of benzene, toluene, n-hexane, trichloroethylene, acetone, ethyl acetate and ethyl alcohol were studied after exposure in human volunteers to those solvents. 1. Solvent concentration in expired air decreased rapidly with time after the cessation of exposure and the decrease was expressed as an equation. Ethyl acetate and ethyl alcohol in expired air decreased faster than did other organic solvents. The decrease was very slow in acetone. 2. Large amounts of retained acetone, benzene and n-hexane were eliminated through the lungs as unchanged solvents, while the amount of eliminated ethyl acetate was almost negligible. 3. The ratio of respiratory elimination to the inhaled (environmental) organic solvent suggested that the determination of respiratory concentration is helpful for estimating environmental benzene, acetone, trichloroethylene and toluene concentration.

The Effect of Organic Additives on the Micelle Formation of Dodecylammonium Halides in Aqueous Solutions

Abstract: The critical micelle concentration (CMC) of dodecyl ammonium halides and the degree of dissociation of the micelle (α) of dodecylammonium chloride were determined as functions of the concentrations of the organic additives by measuring the conductivity and the emf of the following cell: calomel/1 M-KCl/sample solution/AgCl, Ag. The CMC was raised more in the presence of acetone and dioxane than in that of acetamide, formamide, urea, and methanol, and was diminished by adding alcohols (C2–C4). The effect of the alcohols on CMC decreased in the order of the diminished hydration of the counterion, acetone and dioxane were considered to affect the dodecylammonium iodide solution specifically. The dissociation of the micelle was enhanced in the presence of organic additives. Further, we estimated the solubilized amount of the additives from the degree of dissociation of the micelle and attempted to make quantitative estimation of the increment of CMC produced by organic additives.

Bisphenol a synthesis: Kinetics of the phenol‐acetone condensation reaction catalyzed by sulfonic acid resin

Abstract: The industrially important reaction of phenol and acetone to give bisphenol A and water was catalyzed by beads of ion-exchange resin (sulfonated styrene-divinylbenzene copolymer) suspended in a batch reactor containing liquid reactants. The data are summarized by a rate equation accounting for reaction in the resin competitively swollen by water, acetone, phenol, and methylcyclohexane. The catalyst is modeled as two phases, each in equilibrium with the liquid: a polar phase consisting of sulfonic acid groups with hydrogeb–nonded acetone and water and a nonpolar phase consisting of the hydrocarbon matrix swollen with organic components. The rate determining step is the electrophilic attack on phenol in the nonpolar phase by a carbonium ion intermediate in the polar phase. Resin cross-linked with 4% divinylbenzene initially catalyzed acetone conversion at a rate of 5 × 10−4 (moles)/(equiv of acid groups s) at 364°K. An 8% cross-linked resin was much less active because the rigid polymer matrix was only slightly swollen by phenol, but a more highly cross-linked resin with macropores and accessible internal surface catalyzed reaction almost as rapidly as the 4% cross-linked catalyst.

Upper and lower critical solution temperatures in the cosolvent system acetone(1)+ diethyl ether(2)+ polystyrene(3)

Abstract: Phase diagrams for different molecular weight fractions of polystyrene in the mixed solvent system acetone + diethyl ether have been obtained. The system shows a variation of upper and lower critical solution temperatures with solvent composition which indicates the cosolvent nature of the mixed solvent. No solvent composition is found which can dissolve high molecular weight poly-styrene (M106). The separation of critical solution temperatures can be predicted by the Prigogine theory of polymer solution thermodynamics, but not the absolute values.

Organic Solvent Extraction of Liver Microsomal Lipid: II. Effect on the Metabolism of Substrates and Binding Spectra of Cytochrome P-450

Abstract: Extraction of lyophilized liver microsomes from 3-methylcholanthrene- or phenobarbital-treated rats with 1-butanol and acetone removed all the neutral lipids and 80% of the phospholipids; extraction with acetone alone removed all the neutral lipds but only trace amounts of the phospholipids. Recoveries of cytochrome P-450 and NADPH-cytochrome c reductase were 80-90%. Using this extraction procedure we examined several properties of the liver microsomal hydroxylating enzyme system and report the following. (a) Extraction of microsomes with 1-butanol and acetone decreased both 3,4-benzpyrene hydroxylase and benzphetamine N -demethylase activities. Addition of synthetic phosphatidylcholine to the extracted microsomes restored enzymatic activity to control levels. (b) Extraction of microsomes from phenobarbital-treated rats with 1-butanol and acetone increased the magnitude of both the hexobarbital- and benzphetamine-induced type I binding spectra and the ethanol- and phenacetin-induced reverse type I binding spectra. (c) Extraction of microsomes from 3-methylcholanthrene-treated rats with 1-butanol and acetone eliminated the hexobarbital-induced reverse type I binding spectra. (d) Extraction of microsomes from phenobarbital-treated rats with acetone greatly decreased the initial fast phase in the reduction kinetics of NADPH-dependent cytochrome P-450 reductase. Addition of 1 mM benzphetamine to the extracted microsomes restored the initial fast phase. These results indicate that while lipid is required for enzymatic activity, it is not essential for the binding of substrates to cytochrome P-450. In addition, the phenacetin- and ethanol-induced reverse type I binding spectra are not due simply to the displacement of endogenous substrates from cytochrome P-450.

Synthesis of Methyl Isobutyl Ketone from Acetone and Hydrogen Catalyzed by Palladium Supported on Zirconium Phosphate

Abstract: The one-step synthesis of methylisobutyl ketone from acetone and hydrogen was investigated by using palladium supported on zirconium phosphate, a bifunctional catalyst. Effects of reaction variables on both the conversion of acetone and the selectivity of methylisobutyl ketone were examined. The experiments were carried out with a continuous flow unit at 110–140°C and 7–25 kg/cm2 over a range of liquid hourly space velocity of acetone for 2–15 hr−1 with a mole ratio of hydrogen to acetone in the range 0.2–1.45. Under these conditions, the conversion of acetone was 20–40%, the selectivity of methylisobutyl ketone being as much 90–97 mol%. It is suggested that the one-step reaction proceeds via a consecutive mechanism.

Inhibition of bacteria by some volatile and non-volatile compounds associated with milk

Abstract: APT broth inoculated with Streptococcus thermophilus was dispensed into epoxy-lined aerosol cans. Twenty five volatile or non-volatile compounds likely to be present in milk were added individually to cans to attain concentrations in broth of 1, 10, 100, and 1000 ppm of each compound. Compounds used included formic, acetic, butyric, hexanoic, octanoic, and decanoic acid; formaldehyde; acetaldehyde; propionaldehyde; glyoxal; acetone; 2-butanone; diacetyl; propyl- and hexylamine; furfurol; methanol; methylsulfide; methylsulfone; methanethiol; ethanethiol; acetonitrile; chloroform; ether; and ethylenedichloride. Bacteria were enumerated at intervals during incubation at 37 C. Of the six fatty acids tested, decanoic acid was most and hexanoic acid was least inhibitory to S. thermophilus. At 1000 ppm all fatty acids tested always significantly inhibited S. thermophilus. Formaldehyde was more inhibitory to the bacterium than were acetaldehyde, propionaldehyde, or glyoxal. Of the ketones tested, diacetyl was mos...

Thermochemical Isotope Effects. Chloroform/Chloroform-d and Acetone/acetone-d6 in Selected Solvents

Abstract: Isotope effects on the heats of solution of the isotopic pairs chloroform/chloroform-d and acetone/acetone-d/sub 6/ have been measured in a variety of solvents at 25 deg C While both positive and negative isotope effects have been observed for the heats of solution of these solutes, the transfer of the deuterated compound from cyclohexane (at infinite dilution) to other solvents is in every case more exothermic than the transfer of the parent compound (auth)

Process for the preparation of 2,2,6,6-tetramethyl-4-oxopiperidine

Abstract: 2,2,6,6-Tetramethyl-4-oxopiperidine is prepared from 2,2,4,4,6-pentamethyl-2,3,4,5-tetrahydropyrimidine by treatment with an acidic catalyst. Suitable catalysts are Lewis acids, protonic acids and their salts with ammonia or organic bases. The reaction may be carried out in organic solvents, preferably in acetone, by gentle heating, for example at 40° to 65°C. Yields of 95% are obtainable after a reaction of several hours.

Process for producing acrylamide polymers in an acetone-water solvent system

Abstract: A process for producing acrylamide polymers involves polymerization of acrylamide or methacrylamide or polymerizable monovinylic monomers containing predominantly acrylamide or methacrylamide in a mixture of acetone and water in the presence of polyvinyl alcohol, the amount of acetone being from about 23 to 30 %, preferably up to 29.5 %, by weight based on the weight of the acetone-water mixture and the amount of polyvinyl alcohol being from 0.5 to 4 % by weight based on the weight of the polymerizable monomers. The water-soluble acrylamide polymers obtained by this process are in the form of a powder and possess high intrinsic viscosity or high molecular weight so that they are useful as flocculating agents.

Gas phase reactions of acetaldehyde and formaldehyde in the presence of solid catalysts containing fluorine

Abstract: Vapours of acetaldehyde and formaldehyde were passed over silica-alumina catalysts. The catalysts were obtained by soaking silica-alumina with aqueous hydrofluoric acid, the composition of silica-alumina was 75% SiO2, 25% Al2O3. The main products of the reaction were acrolein acetone and propionaldehyde. Also, small amounts of methylethylketone were found in the reaction mixture. It is suggested that the surface of the catalysts studied contains both donor and acceptor sites and also free radical centers.

Gas phase reactions of acetaldehyde and formaldehyde in the presence of mixed solid catlysts containing silica and alumina

Abstract: Acetaldehyde and formaldehyde vapours wer passed over mixed solid oxide catlysts containing silica and alumina in different Al2O3/SiO2 ratios. Acrolein, acetone and propionaldehyde were the main reaction products. Small quantities of methyl ethyl ketone wer found to be present among the products. The correlation between acrolein formation and the Bronsted acidity of the catalysts is discussed.

Hydrogen Redistribution of Acetone on ZnO Catalysts

Abstract: The hydrogen redistribution reaction between d0-acetone and d6-acetone was carried out at −10–60 °C over ZnO catalysts subjected to various modes of pretreatment. The activity of ZnO was several times larger than that of Zn metal, being hardly affected by the conditions of pretreatment below 350 °C and illumination with a mercury lamp. The rate of hydrogen redistribution was proportional to the amount of chemisorbed acetone which obeys the Langmuir adsorption isotherm. The activation heat of redistribution and the heat of acetone chemisorption were estimated to be 14±2 and 10±1 kcal/mol, respectively. The time course of the relative amounts of dn-acetones, independent of the catalyst or its activity, was reproducible by a calculation based on the stepwise exchange model for the hydrogen exchange of acetone. About half of the chemisorbed acetone was found to be active for the redistribution or exchange of hydrogen. From the results and IR spectrometric study of acetone adsorbed on ZnO, the hydrogen redistr...

Autoxidation of Isobutyraldehyde

Abstract: The liquid phase autoxidation of isobutyraldehyde to peroxyisobutyric acid was investigated with ozone as an initiator. The selectivity of the peroxyacid increases with decrease in the amount of aldehyde converted per unit volume of reacting fluid, increase in the ozone feed rate, and decrease in temperature. A few percent of water in solvents increases the selectivity, although too much water brings about a reverse effect. Isopropyl alcohol, acetone, isopropyl formate, propane, propylene, carbon dioxide, and carbon monoxide are observed as by-products besides isobutyric acid. Purified peroxyisobutyric acid (97.2 wt%) was obtained by fractionally distilling the autoxidation product and some of its physical properties were determined. The utility of the peroxyacid as an epoxidizing agent is described.

Metal Phosphinylides and Phosphinothioylides. III. Reactions of Lithium Diphenylphosphinylide and Diphenylphosphinothioylide with Acetone and Bromoacetone

Abstract: Reaction of acetone with [Ph2PO]Li gave 1-hydroxy-1-methylethyl- (2a), 1,1-dimethyl-3-oxobutyldiphenylphosphine oxides (3a) and 2,6-bis(diphenylphosphinyl)-2,6-dimethylheptan-4-one (4a). The corresponding sulfide 2b was obtained in the case of Ph2P(S)H, and 3b and 4b in the case of [Ph2PS]Li (5b). Bromoacetone reacted with 5b through substitution reaction.