Development of Late Transition Metal Insertion Polymerization Catalysts

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Release : 2015
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Book Rating : 240/5 ( reviews)

Development of Late Transition Metal Insertion Polymerization Catalysts - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Development of Late Transition Metal Insertion Polymerization Catalysts write by Tobias Friedberger. This book was released on 2015. Development of Late Transition Metal Insertion Polymerization Catalysts available in PDF, EPUB and Kindle. Polyolefins are the number one commercially produced polymeric material by volume, and find ubiquitous uses as plastics, elastomers, and fibers. They are produced from gaseous olefins such as ethylene and propylene by the action of a transition metal catalyst. Despite tremendous academic and industrial efforts and successes in catalyst development over the past decades, the copolymerization of polar functionalized olefins with sufficiently high activities still remains a largely unsolved issue. Late transition metal catalysts were shown to be more suitable for this kind of polymerization reaction due to their generally lower oxophilic character. The main goal of this thesis was the development of novel late transition olefin polymerization catalysts based on ruthenium and palladium. Prior to this work, only few active olefin polymerization Ru-catalysts were reported. Several series of complexes based on ruthenium were synthesized, characterized and investigated for olefin polymerization. Ru(II)-complexes of the type RuCl2(N,N,N)L with facially coordinating nitrogen donor ligands (N,N,N = trispyridyl-, trispyrazoyl-, trisimidazoyl-methane derivatives) were found to be inactive towards ethylene polymerization. Employing bisanionic disulfonate phosphines as ligands gave Ru-complexes that produced linear, high-molecular weight polyethylene in the presence of an aluminum-alkyl based cocatalyst. Increasing the electrophilicity of the complex, by decreasing the donor strength of the ligand and using higher oxidation state Ru(IV)-complexes, the polymerization activity could be increased, and one of the highest activities for any Ru-based catalyst was observed. Polar additives such as acetone fully inhibited even the most electron-rich catalysts and copolymerization reactions yielded no polymer. In a different approach to solve the same problem, Pd-diimine complexes were modified with pendant olefin and boronate groups. Pd-diimine complexes can facilitate the copolymerization of ethylene with acrylates, and interactions of the pendant Lewis acid group with the functional, Lewis basic comonomer was anticipated to increase catalyst activity. However, no effect of a pendant pinacol boronate was observed on the incorporation ratio of methyl acrylate in room temperature copolymerizations. The ability of the pendant olefin to coordinate to cationic Pd-species resulted in hemilabile effects. Increased catalyst stability at the cost of decreased activities was found in comparison with unfunctionalized ligands.

Late Transition Metal Polymerization Catalysis

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Release : 2006-03-06
Genre : Technology & Engineering
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Book Rating : 266/5 ( reviews)

Late Transition Metal Polymerization Catalysis - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Late Transition Metal Polymerization Catalysis write by Bernhard Rieger. This book was released on 2006-03-06. Late Transition Metal Polymerization Catalysis available in PDF, EPUB and Kindle. At the start of the 1950s, Ziegler and Natta discovered that simple metallorganic catalysts are capable of transforming olefins into linear polymers with highly ordered structures. This pioneering discovery was recognized with a Nobel Prize in 1963. In the 80s and 90s, the development of molecular defined metallocenes led to a renaissance for non-polar polyolefin materials. Designer catalysts allowed a greater precision in defining properties of the material. The past 10 years have seen the discovery of new catalysts based on late transition metals, which allow the combination of polar monomers with non-polar olefins and thus lead to innovative materials. Here, the world's leading authors from industry and academia describe the latest developments in this fascinating field for the first time in such comprehensive detail. In so doing, they introduce readers systematically to the basic principles and show how these new catalysts can effectively be used for polymerization reactions. This makes the book an ideal and indispensable reference for specialists, advanced students, and scientists of various disciplines dealing with research into catalysts and materials science.

Metal Catalysts in Olefin Polymerization

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Release : 2009-02-21
Genre : Science
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Book Rating : 517/5 ( reviews)

Metal Catalysts in Olefin Polymerization - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Metal Catalysts in Olefin Polymerization write by Zhibin Guan. This book was released on 2009-02-21. Metal Catalysts in Olefin Polymerization available in PDF, EPUB and Kindle. Polyolefin is a major industry that is important for our economy and impacts every aspect of our lives. The discovery of new transition metal-based catalysts is one of the driving forces for the further advancement of this field. Whereas the classical heterogeneous Ziegler-Natta catalysts and homogeneous early transition metal metallocene catalysts remain the workhorses of the polyolefin industry, in roughly the last decade, tremendous progress has been made in developing non-metallocene-based olefin polymerization catalysts. Particularly, the discovery of late transition metal-based olefin polymerization catalysts heralds a new era for this field. These late transition metal complexes not only exhibit high activities rivaling their early metal counterparts, but more importantly they offer unique properties for polymer architectural control and copolymerization with polar olefins. In this book, the most recent major breakthroughs in the development of new olefin polymerization catalysts, including early metal metallocene and non-metallocene complexes and late transition metal complexes, are discussed by leading experts. The authors highlight the most important discoveries in catalysts and their applications in designing new polyolefin-based functional materials.

Development of Late Transition Metal Catalysts for Olefin Polymerization

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Release : 2000
Genre : Metal catalysts
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Development of Late Transition Metal Catalysts for Olefin Polymerization - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Development of Late Transition Metal Catalysts for Olefin Polymerization write by Shingo Kikukawa. This book was released on 2000. Development of Late Transition Metal Catalysts for Olefin Polymerization available in PDF, EPUB and Kindle.

Alkene Polymerization Reactions with Transition Metal Catalysts

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Release : 2008-03-10
Genre : Technology & Engineering
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Book Rating : 996/5 ( reviews)

Alkene Polymerization Reactions with Transition Metal Catalysts - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Alkene Polymerization Reactions with Transition Metal Catalysts write by Yury Kissin. This book was released on 2008-03-10. Alkene Polymerization Reactions with Transition Metal Catalysts available in PDF, EPUB and Kindle. During the past 30 years, the field of alkene polymerization over transition metal catalysts underwent several major changes:1. The list of commercial heterogeneous Ziegler-Natta catalysts for the synthesis of polyethylene and stereoregular polyolefins was completely renewed affording an unprecedented degree of control over the polymer structure.2. Research devoted to metallocene and other soluble transition-metal catalysis has vastly expanded and has shifted toward complexes of transition metals with multidentate ligands.3. Recent developments in gel permeation chromatography, temperature-rising fractionation, and crystallization fractionation provided the first reliable information about differences between various active centers in transition-metal catalysts.4. A rapid development of high-resolution 13C NMR spectroscopy resulted in greatly expanded understanding of the chemical and steric features of polyolefins and alkene copolymers. These developments require a new review of all aspects of alkene polymerization reactions with transition-metal catalysts. The first chapter in the book is an introductory text for researchers who are entering the field. It describes the basic principles of polymerization reactions with transition-metal catalysts, the types of catalysts, and commercially manufactured polyolefins. The next chapter addresses the principal issue of alkene polymerization catalysis: the existence of catalyst systems with single and multiple types of active centers. The subsequent chapters are devoted to chemistry and stereochemistry of elemental reaction steps, structures of catalyst precursors and reactions leading to the formation of active centers, kinetics of polymerization reactions, and their mechanisms. The book describes the latest commercial polymerization catalysts for the synthesis of polyethylenes and polypropylene The book provides a detailed description of the multi-center nature of commercial Ziegler-Natta catalysts. The book devotes specialized chapters to the most important aspects of transition metal polymerization catalysts: the reactions leading to the formation of active centers, the chemistry and stereochemistry of elemental polymerization steps, reaction kinetics, and the polymerization mechanism. The book contains an introductory chapter for researchers who are entering the field of polymerization catalysis. It describes the basic principles of polymerization reactions with transition-metal catalysts and the types of commercially manufactured polyolefins and copolymersThe book contains over 2000 references, the most recent up to end of 2006.