Isopropyl alcohol

About: Isopropyl alcohol is a research topic. Over the lifetime, 3064 publications have been published within this topic receiving 27354 citations. The topic is also known as: Rubbing Alcohol & Propan-2-ol.

A direct volumetric method for the analysis of soap

Abstract: Glycol, or preferably its mixture with a solvent for hydrocarbons, such as isopropyl alcohol or chloroform, possesses high solvent power for soaps, which may be directly titrated with strong acids, either potentiometrically or with the use of methyl red or methyl orange. The ionization of the organic acid is suppressed so that salts of weak acids can be directly titrated by this method. The colors of the indicators are brighter and the end-point sharper than those in alcohol or water.

Alkylation reactions over ion-exchanged molecular sieve zeolite catalysts. Part 4.—Competitive alkylation of toluene and benzene with ethanol, n-propyl alcohol, isopropyl alcohol and t-butyl alcohol: consideration of the reactivity and selectivity of the alkylating species

Abstract: Results for the competitive alkylation of toluene and benzene with ethanol, n-propyl alcohol, isopropyl alcohol and t-butyl alcohol over NiY and Ni, SnY zeolite catalysts are reported and analysed. The effects of time on stream, reaction temperature (473–543 K) and space velocity on the positional and substrate selectivity in ethylation under non-isomerizing conditions are examined in detail for catalysts which had already reached their steady-state activity in methylation, a high coking reaction. In all cases the substrate selectivity and ethyltoluene isomer composition (27%para, 22%meta, 51%ortho) remained virtually constant.In contrast to alkylation with ethanol, isomerization of the product alkyltoluenes occurred when n- and iso-propyl alcohol were the alkylating reagents; however, as in ethylation no di- or poly-substituted products were detected.A thorough investigation of the substrate selectivity (reactivity) and para/meta selectivity of the alcohols as alkylating agents is reported, with reference to both the literature on homogeneous Friedel–Crafts alkylation and heterogeneous catalysis and also linear free energy relationships. The high ortho/para ratios and the high quantities of meta isomer obtained indicates that in all cases the alkylating agent is a highly reactive species; the electrophilic character or reactivity is very similar for methylation, ethylation, n-propylation and isopropylation and the isomer distributions obtained in the present work are remarkably similar to those reported in the literature for homogeneous catalysis. Since the alkylating agents had approximately the same reactivity the enormous increase in rates on changing from methanol to isopropyl alcohol as alkylating agent is attributed to the relative quantities of the intermediate carbonium ions on the catalyst surface.

Formation of Furan Fatty Alkyl Esters from their Bis‑Epoxide Fatty Esters

Abstract: Reactions of epoxidized alkyl soyate with four different alcohols: ethanol, isopropyl alcohol, 2-ethylhexanol, benzyl alcohol, in the presence of Bronsted acid catalyst, were investigated. Products, not reported in prior studies of similar reactions, were found. These were furan fatty acid alkyl esters (FFE, mixture of alkyl 8-(5-hexyl-2-furyl) octanoate and alkyl 9-(5-pentyl-2-furyl)nonanoate) which were unambiguously identified by means of GC–MS and two-dimensional NMR. Evidence suggests that the FFE are formed by an acid-catalyzed rearrangement of the epoxidized linoleates. The FFE were formed in presence of all four alcohols tested and in the presence of either sulfuric acid or Amberlyst 15 catalyst. Yields of up to 13 %, as quantified by GC and NMR spectroscopies, were observed.

The Volatiles from Fermentation Product of Tuber formosanum

Abstract: The mycelium of T. formosanum (characterized by DNA analysis) grown in a sterile liquid medium produced some VOCs. The VOCs were analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 23 compounds were identified and quantified. Among them, the main compounds were Dimethyl sulfide (19.82%), Isopropyl alcohol (9.84 ng/l), 2-Butanone (9.24%), Ethanol (7.84%), and 1, 3-Pentadiene (5.46%).