20858-25-7Relevant articles and documents
Efficient concrete foam stabilizer and preparation method thereof
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, (2021/07/17)
The invention discloses an efficient concrete foam stabilizer and a preparation method thereof, according to the efficient foam stabilizer, polyol is subjected to an esterification reaction to form ester bonds, and the ester bonds are connected with amphiphilic side chains, and the number of the amphiphilic side chains is 3-7; one end of the amphiphilic side chain is a hydrophobic chain segment, and the other end of the amphiphilic side chain is a hydrophilic unit; wherein the hydrophobic chain segment is an alkyl chain (R) with 8-14 carbons, and the hydrophilic unit is 2-10 ethylene oxide units. The efficient concrete foam stabilizer is a multi-chain type surfactant, and the multi-chain type surfactant is hydrolyzed under the alkaline condition to release an air-entraining type surfactant. The efficient concrete foam stabilizer has an excellent effect of stabilizing the air content of concrete, meanwhile, hardened concrete has a better pore structure, and the hardening strength of the concrete cannot be greatly influenced.
Aerobic flow oxidation of alcohols in water catalyzed by platinum nanoparticles dispersed in an amphiphilic polymer
Osako, Takao,Torii, Kaoru,Uozumi, Yasuhiro
, p. 2647 - 2654 (2015/02/05)
We have developed a technique for the aqueous aerobic flow oxidation of alcohols in a continuous-flow reactor containing platinum nanoparticles dispersed on an amphiphilic polystyrene-poly(ethylene glycol) resin (ARP-Pt). Various primary and secondary alcohols including aliphatic, aromatic and heteroaromatic alcohols were efficiently oxidized within 73 seconds in a flowing aqueous system at 100-120°C under 40-70 bar of the system pressure to give the corresponding carboxylic acids and ketones, respectively, in up to 99% yield. Benzaldehydes could be also prepared selectively from benzyl alcohols by conducting the flow oxidation under the standard conditions in the presence of triethylamine. Moreover, a practical gram-scale synthesis of surfactants was realized in the aqueous aerobic continuous flow oxidation for 36-116 hours. This aerobic flow oxidation system provides a safe, clean, green, rapid and efficient practical method for oxidizing alcohols.
Chromium(VI) oxide oxidation of non-ethoxylated and ethoxylated alcohols for determination by electrospray ionization mass spectrometry
Beneito-Cambra, Miriam,Bernabe-Zafon, Virginia,Simo-Alfonso, Ernesto F.,Ramis-Ramos, Guillermo
experimental part, p. 2093 - 2100 (2011/11/06)
A new derivatization procedure to increase the sensitivity of electrospray ionization mass spectrometry (ESI-MS) to non-ethoxylated and ethoxylated alcohols was investigated. The analytes were oxidized with chromium(VI) oxide and the resulting carboxylic and ethoxy-carboxylic acids were isolated by extraction with ethyl acetate; the extracts were alkalinized and infused into the ESI-MS system working in the negative-ion mode. The yields of the combined oxidation-extraction were ca. 100% for non-ethoxylated fatty alcohols dissolved in acetone and they decreased moderately in samples containing increasing amounts of water (e.g., a 75% yield was obtained with 50% water). Ethoxylated alcohols with more than two ethylene oxide units resulted in yields of ca. 60%. Low limits of detection (LODs) were obtained when the procedure was applied to the analysis of body- care products and cosmetics containing fatty alcohols, e.g., in a varicose-vein cream, the LODs were 25 μ cetyl alcohol and 7.5 μ stearyl alcohol (detected as palmitic acid and stearic acid, respectively) per gram of sample. High molecular mass alcohols were also detected in seawater after pre- concentration by solid-phase extraction. Thus, the proposed method is particularly valuable for use in industrial samples having complex matrices and in environmental samples and it is competitive with other methods for the analysis of trace amounts of fatty alcohols.
Extraction of Zn(II), Cd(II), and Hg(II) by dodecyloligo(oxyethylene) carboxylic acids
Strzelbicki, Jerzy,Charewicz, Witold,Beger, Jorg,Hinz, Lutz
, p. 1695 - 1700 (2007/10/02)
The synthesis of a series of n-dodecyloligo(oxyethylene) carboxylic acids of general formula C12H25(OCH2CH2)nOCH2COOH (n=0 to 5) and application of these compounds for the separation of Zn(II), Cd(II), and Hg(II) in extraxtion are reported.Negligible extractability of the metal ions investigated was found using dodecyloxyacetic acid (n=0) which indicated that complexation resulted from metal-cation interaction with oxygen atoms of the polyoxyethylene chain incorporated into the molecule of complexon.In extractions from aqueous solutions containing ZnCl2, CdCl2, HgCl2, and NaOH (pH regulator), loading of the organic phases increased for extractants with more oxyethylene units.In particular, Hg(II) extractibility and molecular structure of the extractant are related.The selectivity of extraction increased drastically if NaCl was added to the initial aqueous phase, as the extractibilities of Cd(II) and, particularly, Hg(II) declined while the extractibility of Zn(II) remained high.Selectivity of extraction is produced by the complex chemical equilibria resulted from complexation of the metal cation by an alkyloligoether carboxylic acid in the organic phase and by Cl(1-) and OH(1-) anions in the aqueous phase.Thus, aqueous solution parameters greatly influence the efficiency and selectivity of the extraction process and suitable experimental conditions are very important.
