Download or read book Designing Octahedral Group 4 Complexes as Catalysts for Polymerization Processes written by and published by . This book was released on 2009 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Group 4 Metal Octahedral Complexes as Catalysts for Olefin Polymerization written by Marina Lamberti and published by . This book was released on 2003 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stereoselective Polymerization with Single Site Catalysts written by Lisa S. Baugh and published by CRC Press. This book was released on 2007-11-29 with total page 698 pages. Available in PDF, EPUB and Kindle. Book excerpt: New synthetic techniques allow chemists to modify polymer microstructures more precisely than ever, making it possible to design materials that meet increasingly demanding performance requirements. Written and edited by experts in the field, Stereoselective Polymerization with Single-Site Catalysts reviews how the relative stereochemistry of
Download or read book New Group Four Complexes and Their Use as Homogeneous Polymerization Catalysts for the Production of Polyolefins written by John J. Esteb and published by . This book was released on 2001 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oxygen Based Group 4 Complexes as Catalysts for Olefin and Styrene Polymerization written by Carmine Capacchione and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Group 4 Complexes Bearing Tridentate Aryloxide Based Ancillary Ligands written by Ka-Ho Tam and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Group 4 Complexes Bearing Tridentate Aryloxide-based Ancillary Ligands: Synthesis, Characterization and Application as Olefin Polymerization Catalysts" by Ka-ho, Tam, 譚家豪, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled GROUP 4 COMPLEXES BEARING TRIDENTATE ARYLOXIDE- BASED ANCILLARY LIGANDS: SYNTHESIS, CHARACTERIZATION AND APPLICATION AS OLEFIN POLYMERIZATION CATALYSTS Submitted by Tam Ka Ho for the degree of Doctor of Philosophy at The University of Hong Kong in 2006 The preparation, characterization, crystal structures and olefin polymerization behavior of a class of Group 4 complexes, and in particular the Zr(IV) derivatives 1 1 [Zr(L )Cl (D)] [H L = 2,6-di(3-tert-butyl-5-methylphen-2-ol)pyridine; D = ethers, 2 2 ketones and Cl(HPR )], have been undertaken. These [O, N, O] catalysts exhibit excellent activities with MAO for ethylene polymerization. Studies to assess the impact of the donor group during catalysis suggest that the same active species is generated and the donor does not play an active role. Superior activities were observed with the Bu Al/Ph CB(C F ) cocatalyst in ethylene polymerization and - 3 3 6 5 4 -1 -1 propylene copolymerization (36,590 and 15,700 g mmol h respectively). Insight into the behavior of the catalytic system with MAO has been derived from gel permeation chromatography and NMR analyses of the polymers prepared under 1 13 different reaction conditions. H and C NMR end-group analyses reveal resonances for saturated methyl chain-end groups only, and undetectable levels of unsaturated vinyl chain ends. This indicates that for the polymerization chain-transfer mechanism, the conventional β-H transfer reactions are insignificant and the unusual chain transfer to Al pathway is vastly dominant. Group 4 complexes supported by unsymmetric tridentate [O, N, O] ligands bearing different substituents on the two aryloxide rings have been prepared, in order to develop new catalytic systems capable of stereospecific α-olefin polymerization. Their activities for ethylene polymerization with MAO are significantly lower than the symmetric [O, N, O] analogues. A number of group 4 bis(benzyl) complexes supported by tridentate pyridine-2- phenolate-6-aryl [O, N, C] ligands, with alkyl and halogen substituents at the R position ortho to the metal, have been prepared. This enabled direct comparison with the CF -substituted [O, N, C] analogues, which were recently reported to exhibit novel C-H---F-C contacts in solution with potential applications for attractive ligand---polymer interactions. The molecular structure of the Zr derivative bearing an ortho-Cl group was determined, revealing the benzyl moieties in an unusual 'anti, anti' configuration. Saliently, this polyethylene catalyst in conjunction with Bu Al/Ph CB(C F ) displayed the best activity thus far observed for [O, N, C] 3 3 6 5 4 -1 -1 catalysts (8630 g mmol h ). A series of group 4 bis(benzyl) complexes supported by newly designed [O, C, N] ligands bearing R substituents ortho to the metal has been prepared, such that the σ- aryl moiety resides trans to the alkyl/polymer chain, and catalyst decomposition pathways such as olefin insertion into the M-C(sp ) bond are impeded. The crystal structure of the CF -substituted hafnium(IV) complex features weak intramolecular 31 C-H---F-C (CF ---methylene) interactions. The H NMR spectra of [M(O, C, N- CF )(CH Ph) ] analogues revealed coupling (assigned to J [via M---F] for Hf and
Download or read book Polymeric Chiral Catalyst Design and Chiral Polymer Synthesis written by Shinichi Itsuno and published by John Wiley & Sons. This book was released on 2011-06-28 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews chiral polymer synthesis and its application to asymmetric catalysis. It features the design and use of polymer-immobilized catalysts and methods for their design and synthesis. Chapters cover peptide-catalyzed and enantioselective synthesis, optically-active polymers, and continuous flow processes. It collects recent advances in an important field of polymer and organic chemistry, with leading researchers explaining applications in academic and industry R & D.
Download or read book New Group Four Organometallic Complexes and Their Use as Homogeneous alpha olefin Polymerization Catalysts written by Patrick Foster and published by . This book was released on 1997 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Octahedral Bis phenolate Ether Group IV Metal Complexes for Polymerization and Copolymerization of Alpha olefins written by Elizabeth Tanzini Kiesewetter and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Octahedral group IV bis(phenolate) ether complexes, activated by methylaluminoxane, are highly active and stereospecific [alpha]-olefin polymerization catalysts. X-ray crystallographic analysis reveals the Zr and Hf complexes to be closely isostructural; the bond lengths of the Hf complex are slightly shorter, but the maximum deviation is only 0.062 Å. Despite the structural similarity of the Hf and Zr complexes, the Hf complexes generate more highly stereoselective catalysts. In addition to the influence of the transition metal, the structure of the ligand has a large influence on the stereospecificity. Bis-t-Butyl phenyl substituted complexes of Hf and Zr, when activated by MAO at 50 - 80 °C, generate high molecular weight polypropylene (Mn = 130,000 - 360,000 g/mol) with isotacticities [mmmm]> 0.97 and melting points as high as 165°C. Octahedral group IV bisphenolate ether complexes, activated by methylaluminoxane, were also tested in propylene polymerization in the presence diethyl zinc. Although the Hf and Zr complexes are structurally similar, propylene polymerization behavior of the two catalysts differs significantly in terms of productivity, isospecificity and propensity to incorporate specific regioerrors. 13C-NMR analysis revealed that the type and the number of regioerrors being incorporated into the polymer chain are strongly dependent on the identity of the ligand and the metal. Low molecular weight polypropylene oligomers (Mn = 1700 - 9900 g/mol), generated in the presence of diethyl zinc facilitated end group analysis, which revealed the presence of isobutyl and 2-methylbutyl groups. Octahedral bis(phenolate) catalysts are highly active catalysts for the isospecific polymerization of 1-hexene and the production of high molecular weight ethylene/1-hexene copolymers. These catalysts are active for the production of high molecular weight copolymers even at high temperatures. The reactivity ratios for these complexes were determined; all of the bis(phenolate) complexes tested showed reasonable 1-hexene incorporations. The complexes prepared from the more sterically demanding ligands showed higher incorporations of comonomers than those prepared from the less sterically demanding ligands. Complexes of the type Cp*TiX2(ONR'R'') (Cp* = [Eta]5-C5Me5, X = Me, Cl; R = Et, TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl); X = R' = Me, R'' = tBu) were synthesized by several routes. Upon activation with [Ph3C]+[B(C6F5)4]- and AliBu3, these complexes generate highly active catalysts for propylene polymerization, although significant catalyst deactivation was observed. Activation with B(C6F5)3/AliBu3 or methylaluminoxane (MAO) resulted in reduced polymerization activity; the latter leading to increased catalyst lifetime. Reaction of Cp*Ti(Me)2(ONEt2) and Cp*Ti(Me)2(ONtBu(Me)) with B(C6F5)3 resulted in clean formation of the zwitterionic contact ion pairs, [Cp*Ti(Me)([Eta]2-ONEt2)]+[MeB(C6F5)3]- and [Cp*Ti(Me)([Eta]2-ONtBu(Me))]+[MeB(C6F5)3]- respectively whereas reaction of Cp*Ti(Me)2([Eta]2-ONtBu(Me)) with [Ph3C]+[B(C6F5)4]- resulted in the clean formation of the solvent-separated ion pair [Cp*Ti(Me)([Eta]2-ONtBu(Me))]+[B(C6F5)4]-. Addition of AliBu3 or AlMe3 to the cationic [Cp*Ti(Me)(ONtBu(Me))]+[B(C6F5)4]- resulted in decomposition of the cations.
Download or read book Synthesis and Characterization of Group 4 Complexes and Olefin Polymerization Catalysts Supported by Chelating V aryl Ligands written by Chun Yu Lo and published by . This book was released on 2009 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Group 4 Metal Octahedral Bis phenolate Complexes for Propylene Polymerization written by Madalyn Radlauer and published by . This book was released on 2008 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Design and Synthesis of Group IV and Group XIII Complexes as Polymerisation Catalysts written by Lucy Kathryn Burdsall and published by . This book was released on 2004 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Methods for Polymers written by Masoud Soroush and published by MDPI. This book was released on 2020-12-10 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents recent advances in computational methods for polymers. It covers multiscale modeling of polymers, polymerization reactions, and polymerization processes as well as control, monitoring, and estimation methods applied to polymerization processes. It presents theoretical insights gained from multiscale modeling validated with exprimental measurements. The book consolidates new computational tools and methods developed by academic researchers in this area and presents them systematically. The book is useful for graduate students, researchers, and process engineers and managers.
Download or read book Olefin Polymerization Using Group 4 Cyclopentadienyl amido Catalysts written by Andrew Leland McKnight and published by . This book was released on 1997 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Group 4 Amidinate Complexes as Olefin Polymerisation Catalysts written by Richard T. W. Scott and published by . This book was released on 2013 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polypropylene Handbook written by József Karger-Kocsis and published by Springer. This book was released on 2019-03-18 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book extensively reviews Polypropylene (PP), the second most widely produced thermoplastic material, having been produced for over 60 years. Its synthesis, processing and application are still accompanied by vigorous R&D developments because the properties of PP are at the borderline between those of commodity and engineering thermoplastics. Readers are introduced to various tacticities and polymorphs of PP, and their effects on structural properties. Further, the book addresses the control of optical properties using nucleants, provides strategies for overcoming the limited cold/impact resistance of PP, examines in detail the effects of recycling, and presents guidelines for the property modification of PPs through foaming, filling and reinforcing with respect to target applications. Special attention is paid to descriptions and models of properties as a function of morphological variables. Last but not least, the book suggests potential practical applications of PP-based systems, especially in the packaging, appliances, building/construction, textile and automotive sectors. Each chapter, written by internationally respected scientists, reflects the current state-of-art in the respective field and offers a vital source of information for students, researchers and engineers interested in the morphology, properties, testing and modeling of PP and PP-based systems. The content is indispensable to the appropriate application of PPs and related composites.
Download or read book Group 4 Complexes Bearing Tridentate Aryloxide based Ancillary Ligands written by Ka-ho Tam and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
