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Catalyst Productivities (catalyst + productivity)
Selected AbstractsHighly Selective Biphasic Telomerization of Butadiene with Glycols: Scope and LimitationsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11 2003Arno Behr Abstract Highly selective telomerization reactions of a number of short-chain glycol nucleophiles with 1,3-butadiene have been achieved in aqueous biphasic systems employing the water-soluble catalyst system Pd(acac)2/TPPTS. For all substrates the selectivity for the obtained monotelomers 5,7 reached ,95% whereas butadiene dimers 3, octadienols 4 and ditelomers like 2 were produced only in trace amounts. The order of reactivity is ethylene glycol>>1,3-propylene glycol , glycerol>1,4-butylene glycol, which is in agreement with generally observed trends. The scope and limitations of these reactions are discussed in terms of obtained yields and achievable catalyst productivities (total turnover numbers). [source] On-line monitoring and fingerprint technology: new tools for the development of new catalysts and polyolefin materialsMACROMOLECULAR SYMPOSIA, Issue 1 2004Arno Tuchbreiter Abstract The High-Output Polymer Screening (HOPS) combines process-relevant automated reactor systems and rapid polymer characterization with on-line polymerization monitoring and automated data acquisition ("electronic notebook") in order to make effective use of advanced data mining tools. This has led to the development of fingerprint technology based upon correlations between spectroscopic data and polymerization process conditions, catalyst compositions, as well as polymer end-use properties. Infrared spectroscopic fingerprints proved to be very useful for accelerating polymer analyses including characterization of polymer molecular architectures as well as non-destructive testing of the mechanical, thermal and other end-use polymer properties. Such spectroscopic fingerprints represent important components of effective on-line quality control systems. With ATR-FT-IR probes on-line monitoring of catalytic olefin copolymerization was performed in solution to measure in real time copolymerization kinetics, catalyst productivities, catalyst deactivation as well as copolymerization parameters and copolymer sequence distributions. Monomer consumption and comonomer incorporation were monitored simultaneously. Advanced fingerprint technology can reduce significantly the need for time- and money consuming polymer testing and can also stimulate the search for new catalyst systems and polymeric materials. [source] Ruthenium-Catalyzed Alkyne Oxidation with Part-Per-Million Catalyst LoadingsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2010Wei Ren Abstract Using a catalytic system of the (cymene)ruthenium dichloride dimer, [Ru(cymene)Cl2]2, (0.001,mol%) and iodine (10,mol%), a variety of alkynes bearing different functional groups were oxidized with tert -butyl hydroperoxide (TBHP; 70% solution in water) under mild conditions to give 1,2-diketones in good to excellent yields. Two noteworthy features of the method are the extremely high catalyst productivity (TON up to 420,000) and scale-up to 1,mol. Preliminary mechanism investigations showed that iodonium ion and water were involved in the transformation. [source] Copolymerization of ethylene with 1-hexene over metallocene catalyst supported on complex of magnesium chloride with tetrahydrofuranJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2004Krystyna Czaja Abstract The study of ethylene/1-hexene copolymerization with the zirconocene catalyst, bis(cyclopentadienyl)zirconium dichloride (Cp2ZrCl2)/methylaluminoxane (MAO), anchored on a MgCl2(THF)2 support was carried out. The influence of 1-hexene concentration in the feed on catalyst productivity and comonomer reactivity as well as other properties was investigated. Additionally, the effect of support modification by the organoaluminum compounds [(MAO, trimethlaluminum (AlMe3), or diethylaluminum chloride (Et2AlCl)] on the behavior of the MgCl2(THF)2/Cp2ZrCl2/MAO catalyst in the copolymerization process and on the properties of the copolymers was explored. Immobilization of the Cp2ZrCl2 compound on the complex magnesium support MgCl2(THF)2 resulted in an effective system for the copolymerization of ethylene with 1-hexene. The modification of the support as well as the kind of organoaluminum compound used as a modifier influenced the activity of the examined catalyst system. Additionally, the profitable influence of immobilization of the homogeneous catalyst as well as modification of the support applied on the molecular weight and molecular weight distribution of the copolymers was established. Finally, with the successive self-nucleation/annealing procedure, the copolymers obtained over both homogeneous and heterogeneous metallocene catalysts were heterogeneous with respect to their chemical composition. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2512,2519, 2004 [source] | ||||||||||