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Experimental Techniques - 相似文献
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Ohne Zusammenfassung 相似文献
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Patrick‐Kurt Dannecker Dr. Ursula Biermann Dr. Marc von Czapiewski Prof. Dr. Jürgen O. Metzger Prof. Dr. Michael A. R. Meier 《Angewandte Chemie (International ed. in English)》2018,57(28):8775-8779
Herein, a novel approach is reported for the synthesis of medium‐ and long‐chain aliphatic polyethers 2 based on the GaBr3‐catalysed reduction of polyesters 1 with TMDS as the reducing agent. Thus, various linear and branched aliphatic polyesters 1 were prepared and systematically investigated for this reduction strategy, demonstrating the applicability and versatility of this new polyether synthesis protocol. Medium‐ and long‐chain chain polyethers were obtained from the respective polyesters without or with minor chain degradation, whereas short‐chain polyesters, such as poly‐l ‐lactide 1 i and poly[(R)‐3‐hydroxybutanoate] 1 j , showed major chain degradation. In this way, previously unavailable and uncommon polyethers were obtained and studied. 相似文献
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Aslam Ali M. Sproull Robert D. Laver Murray L. Biermann Christopher J. 《Applied biochemistry and biotechnology》1989,(1):135-148
The production of oxalic acid by the catalytic oxidation of Douglas-fir (Psedotsuga menfiesii (Mirb) Franco) bark and subsequent pyrolysis of the residue to produce high density carbon pellets is discussed. Kinetic rate data are
presented for oxalic acid production from Douglasfir bark. A maximum yield of 38 wt% oxalic acid has been obtained in 8 h
at 80°C with 62.5 vol% HNO3 and 0.5 mg V2O5/g of bark. Additional oxalic acid can be produced by the conversion of pyrolytic oils and tars (obtained during carbonization
of the residue) to increase the total yield to 45 wt%. An economic analysis based on the current cost of oxalic acid indicates
the viability of the proposed process. 相似文献
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Yakov S. Vygodskii Olga A. Mel'nik Elena I. Lozinskaya Alexander S. Shaplov Inna A. Malyshkina Nadejda D. Gavrilova Konstantin A. Lyssenko Mikhail Yu. Antipin Denis G. Golovanov Alexander A. Korlyukov Nikolai Ignat'ev Urs Welz‐Biermann 《先进技术聚合物》2007,18(1):50-63
Various 1,3‐dialkylimidazolium and tetraalkylphosphonium ionic liquids (ILs), including novel ones, have been studied as reaction media for free radical polymerization of methyl methacrylate (MMA), acrylonitrile (AN) and 1‐vinyl‐3‐ethylimidazolium salts (ViEtIm+)Y?. The influence of IL's nature upon the polymer formulation was investigated. The use of different ionic liquids allows not only to obtain the polymers with high molecular weight (PMMA, up to 5,770,000 g/mol; PAN, up to 735,000 g/mol and poly[(ViEtIm+)Y?], up to 1,130,000 g/mol) in high yields, but also to control the polymerization rate and molecular mass. The physicochemical characteristics, including mechanical properties, thermal stability and heat‐resistance of the obtained polymers were studied in order to compare with those of polymers prepared in a traditional media. It was found that elongation, tensile modulus and strength of PAN, which was synthesized in ionic liquid, are reliatively higher. The influence of IL's nature upon their ionic conductivity and the formation of conductive polymers from molten‐salt‐type vinyl monomers was investigated. Molecular design of the polymers simultaneously with the influence of IL's nature in order to achieve higher ionic conductivity is discussed. Flexible, transparent polymer films, obtained in different ways, show relatively high ionic conductivity (of about 10?5 S cm?1 at 20°C). Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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