Polymerization of 1,3-butadiene with VO(P-204)(2) and VO(P-507)(2) activated by alkylaluminum

The oxovanadium phosphonates (VO(P-204)(2) and VO(P-507)(2)) activated by various alkylaluminums (AlR3, R = Et, i-Bu, n-Oct; HAIR(2), R = Et, i-Bu) were examined in butadiene (Bd) polymerization. Both VO(P-204)(2) and VO(P-507)(2) showed higher activity than those of classical vanadium-based catalysts (e.g. VOCl3, V(acac)(3)). Among the examined catalysts, the VO(P-204)(2)/Al(Oct)(3) system (I) revealed the highest catalytic activity, giving the poly(Bd) bearing M-n of 3.76 x 10(4) g/mol, and M-w/M-n ratio of 2.9, when the [Al]/[V] molar ratio was 4.0 at 40 degrees C. The polymerization rate for I is of the first order with respect to the concentration of monomer. High thermal stability of I was found, since a fairly good catalytic activity was achieved even at 70 degrees C (polymer yield > 33%); the M-n value and M-w/M-n, ratio were independent of polymerization temperature in the range of 40-70 degrees C. By IR and DSC, the poly(Bd)s obtained had high 1,2-unit content (> 65%) with atactic configuration. The 1,2-unit content of the polymers obtained by I was nearly unchanged, regardless of variation of reaction conditions, i.e. [Al]/[V], ageing time, and reaction temperature, indicating the high stability of stereospecificity of the active sites.

Resolución No. 204: Por la cual se resuelve un trámite de revocatoria

Servicios registrales

Miller Family Papers - Accession 204 - M90 (115-116)

The Miller Family Papers consist of notes on the Miller, Cathcart, and Roddey families, genealogical data on the Lindsay, Stewart, and McCaughrin families, and an American Civil War reminiscence of William Joseph Miller entitled, “My Experience as a Soldier in the Confederate Army. Written at the Request of Barnette, My Only Living Daughter.” Miller served in the 12th Regiment, South Carolina Volunteers of the Confederate Army.

The Probe, Issue 204 - September 1999

USFWS to Explore Canada Goose Management Strategies -- from a press release issued Aug. 3 by the US. Fish & Wildlife Service, written by Chris Tollefson. Anti-Trapping Measure Passes House Oregon Legislature Moves To Ensure Safety Of Its Citizens Against Cougars Acord Promoted Away From Wildlife Services New State Director US DA/APHIS in Mississippi is Kristina Godwin BOOk R e v i e w : "Living With Wildlife: How to Enjoy, Cope With, and Protect North America's Wild Creatures Around Your Home and Theirs," The California Center for Wildlife, with Diana Landau and Shelley Stump. San Francisco: A Sierra Club Book. 1994. 340 pp. + index $15.00. French Shepherds Protest Predators Rabbit Calicivirus Kills 65% of Rabbit Population Abstracts from the 2nd International Wildlife Management Congress, Hungary Crop Damage by Wildlife in Northern Ghana – O. I. Aalangdon* and A.S. Langyintuo, *Dept. of Renewable Natural Resources, University for Development Studies, Tamale Northern Region, Ghana Large Predators in Slovenia On the Way from Near Extermination to Overprotection and Back: Is Conservation Management of Large Predators in Cultural Landscapes Possible At All? -- M. Adamic, Chair of Wildlife Ecology, Biotechnical Faculty, University of Ljubljana, Slovenia Human-wolf Conflicts in the East Baltic: Past, Present, and Future -- Z. Andersone*, L. Balciauskas, and H. Valdmann., *Kemeri National Park, KemeriJurmala, Latvia Gray Wolf Restoration in the Northwestern United States -- E.E. Bangs*, J.A. Fontaine, D.W. Smith, C. Mack, and C. C. Niemeyer, *U.S. Fish & Wildlife Service, Helena, MT The Impact of Changing U.S. Demographics on the Future of Deer Hunting -- R. D. Brown, Wildlife & Fisheries Sciences, Texas A&M University, College Station, TX Management of Overabundant Marcropods in Nature Reserves: 6 Case Studies from Southeastern Australia -- G. Coulson, Dept. of Zoology,University of Melbourne,Parkville, Victoria, Australia

Ms. hebr. oct. 204 - Perush ha-Torah

Vorbesitzer: Eljāqīm Carmoly

Na 50 Nachlass Arthur Schopenhauer - 'Schopenhauer-Archiv', 204 - Antwortschreiben zur Frage der Bedeutung von Immanuel Kant

u.a.: Rücksprache mit Professor Schubert; Nachlass Immanuel Kant; Kritik an Hegel in "Der Wille in der Natur";

8° Hs 204 - Medizinische Sammelhandschrift

Vorbesitzer: Johann Ludwig Choulant; Senckenbergische Bibliothek Frankfurt am Main

Ms.Ff.F.Stoltze 3. 204 - Brief von Martin Ochs an Friedrich Stoltze

Bernhard Schnapper, Frankfurter Latern, Krebbelzeitungen, Nizza

Na 1 Nachlass Max Horkheimer, 577 - Korrespondenzen mit Friedrich (Frederick) Pollock (p. VI 32, 204-409)

1 Brief von Max Horkheimer an Edwin S. Bingham, 03.05.1942; 1 Brief von Frederick Pollock an A. P. Bersohn, 12.03.1942; 1 Brief von Austin P. Evans an Frederick Pollock, 26.02.1942; 1 Brief von Alice H. Maier an Max Horkheimer, 10.02.1942; 1 Brief von Franz Neumann an Frederick Pollock, 02.02.1942; 1 Brief von Frederick Pollock an Moritz Bonn, [1942];