Acetone

About: Acetone is a research topic. Over the lifetime, 9458 publications have been published within this topic receiving 120867 citations. The topic is also known as: propanone & dimethylketone.

Novel aryl oxalate esters for peroxyoxalate chemiluminescence reactions

Abstract: Six oxalate esters of 2-nitro-4-alkoxycarbonylphenol and 2-alkoxycarbonyl-4-nitrophenol were synthesised for use in the peroxyoxalate chemiluminescence reactions that take place via several steps with 4-hydroxy-3-nitrobenzoic acid and 5-nitrosalicylic acid as starting materials, respectively. The addition of ethylene glycol to the alkoxy moiety enhanced the solubility in solvents such as acetone, acetonitrile and ethyl acetate. When reacted with hydrogen peroxide in the presence of a fluorescent compound, perylene, they gave similar chemiluminescence reaction curves to those of DNPO [bis(2,4-dinitrophenyl) oxalate] and TCPO [bis(2,4,6-trichlorophenyl) oxalate]. Among them, bis[4-nitro-2-(3,6,9-trioxadecyloxycarbonyl)phenyl] oxalate was found to be the best for the high-sensitivity detection of both hydrogen peroxide and fluorescent compounds using the peroxyoxalate chemiluminescence reaction because of its extreme solubility in solvents such as acetone (767 mM) and acetonitrile (1010 mM).

Use of solvent mixtures in supercritical antisolvent process to modify precipitates morphology: Cellulose acetate microparticles

Abstract: In the supercritical antisolvent precipitation (SAS), the jet fluid dynamics is characterized by two-phase mixing at subcritical conditions, and by one-phase mixing at completely developed supercritical conditions. The amplitude of the pressure range, in which binary systems organic solvent/scCO 2 exhibit the transition between two-phase to one-phase mixing, depends on the organic solvent that is in contact with supercritical carbon dioxide (scCO 2 ) and conditions the morphology of the microparticles produced by SAS. When this pressure range is wide, as in the case of dimethylsulfoxide (DMSO), solutes solubilized in the organic solvent can be precipitated as microparticles by atomization, droplets formation and drying; when this pressure range is narrow, as for acetone, gas mixing prevails and only nanoparticles are generally observed. Therefore, generally speaking, solutes that are soluble only in solvents exhibiting gas mixing in scCO 2 , do not exhibit microparticles morphology and this fact is a limitation for several industrial applications. In this work, a model compound, cellulose acetate (CA), that is slightly soluble in DMSO and freely soluble in acetone, was processed by SAS using mixtures of the two solvents that exhibit intermediate behaviors between the two pure solvents, to extend two phase mixing and produce CA microparticles. Using different DMSO/acetone mixture percentages, the effects of the polymer concentration in the liquid solution and of the pressure were studied. A mixture of DMSO/Acetone 50/50 (v/v), at a pressure of 85 bar and a concentration of the liquid solution equal to 40 mg/mL, efficiently produced non-coalescing CA microparticles with a mean diameter of 0.42 μm and a standard deviation of about 0.15 μm, demonstrating that this SAS strategy can be successful.

Acidity Constants of Some Tetrazole Compounds in Various Aqueous−Organic Solvent Media

Abstract: The acidity constants of some tetrazole compounds were determined pH-metrically at 25 °C and at the constant ionic strength I = 0.1 mol dm-3 (KNO3) in pure water as well as in various aqueous mixtures having variable mole fractions (0.05−0.3) of organic solvents. The organic solvents used are methanol, ethanol, N,N-dimethylformamide, dimethyl sulfoxide, and acetone. Generally, the pKa values increase with an increase in the content of the organic solvent. It was concluded that the major effects responsible for this behavior are, in addition to the electrostatic effect, the stabilization of the conjugate base by hydrogen-bonding interactions with solvent molecules and solvent basicity. Effect of molecular structure of tetrazoles on the pKa values is discussed. Moreover, the thermodynamic functions (ΔH, ΔG°, and ΔS°) associated with the ionization process of investigated compounds in a pure aqueous medium are derived and their values are discussed.

A Study of Some New Acidizing Inhibitors on Corrosion of N-80 Alloy in 15% Boiling Hydrochloric Acid

Abstract: Three new organic inhibitors, namely, dicinnamylidene acetone (DCA), disalicylidene acetone (DSA), and divanillidene acetone (DVA), were synthesized in the laboratory and their inhibiting ...

One-step methyl isobutyl ketone (MIBK) synthesis from 2-propanol: Catalyst and reaction condition optimization

Abstract: A gas-phase process for methyl isobutyl ketone (MIBK) synthesis from 2-propanol in one-pot is studied as an alternative to the conventional technology for producing MIBK from acetone (DMK). Bifunctional copper/acid–base catalysts able to operate at mild temperatures and atmospheric pressure were prepared and characterized by measuring the acid and base properties as well as the metal dispersion. It was found that a Cu-Mg-Al mixed oxide catalyst gives high MIBK yields. In this catalyst, the metal fraction in loadings of 2–6 wt% promotes the hydro-dehydrogenation steps at high rates whereas the surface acid–base sites of moderate acid and base properties favor the aldol condensation reaction. The effect of different operational conditions such as reaction temperature and reactant partial pressure was also investigated. The MIBK formation rate was enhanced by increasing 2-propanol partial pressure in a wide range, consistently with a positive 2-propanol reaction order in the overall kinetics whereas the presence of hydrogen in the reactant mixture inhibited MIBK synthesis due to a negative order with respect to H 2 . An increase of the reaction temperature and the use of inert atmosphere improved the MIBK yield. By operation at 533 K in N 2 the Cu-Mg-Al catalyst with 6.4 wt% Cu, yields 27% MIBK in comparison to the 30% typically obtained in current commercial liquid-phase high-pressure processes from DMK.