Structural And Chemical Modification Of Late Transition Metal Olefin Polymerization Catalysts

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.

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.

This compilation provides advanced graduate students and researchers with a structured overview of olefin polymerization. Divided into eight chapters written by international experts, this book covers polymerization using various organotransition-metal catalysts, including early and late transition metal complexes, new trends in olefin oligomerization and related reactions. All authors address the historic and scientific backgrounds of the field as well as current research progress and potential for further research. The complete book is designed to present eight independent lectures and, because all authors are well versed in organometallic chemistry, each is based on a profound understanding of the reactions and structures of organotransition metal complexes. This book is an ideal accompaniment for researchers taking courses in olefin polymerization and also serves as a valuable resource for teachers and lecturers of chemistry when planning and researching material for advanced lecture courses.

More than 30 years after the discovery of transition metals and organometal lics as catalysts for olefin polymerization these catalysts did not have lost their fascination. Since 1953 when Karl Ziegler has discovered the catalytic polymerization of ethylene leading to plastically formable polymers which are mechanically stable up to temperatures of about 100°C, synthetic polymers and rubbers have made their way right into private houses. This discovery has been a main impetus for the fast growing production of plastics. The stereoselective poly merization of propylene and other long-chain a-olefins first detected by Giulio Natta leads to an even broadened field of applications. Another enforcing factor were the developments of Standard Oil of Indiana and Phillipps Petroleum Company who engaged in the polymerization of a-olefins supported molybdenum, cobalt and later on chromium catalysts which clearly indicates the wide variety of suitable systems. This kind of research acknowledged merit when in 1963 the Nobel prize of chemistry was awarded to Ziegler and Natta. Although to a great extent there is a technical application for these catalysts, up to now the nature of the active centres and many reaction mechanisms are not completely known.

Including recent advances and historically important catalysts, this book overviews methods for developing and applying polymerization catalysts – dealing with polymerization catalysts that afford commercially acceptable high yields of polymer with respect to catalyst mass or productivity. • Contains the valuable data needed to reproduce syntheses or use the catalyst for new applications • Offers a guide to the design and synthesis of catalysts, and their applications in synthesis of polymers • Includes the information essential for choosing the appropriate reactions to maximize yield of polymer synthesized • Presents new chapters on vanadium catalysts, Ziegler catalysts, laboratory homopolymerization, and copolymerization

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.

The discoveries of organometallic catalysts for olefin polymerization by Karl Ziegler and that of stereoregular olefin polymers by Giulio Natta are probably the two most important achievements in the areas of catalysis and polymer chemistry in the second half of this century. They led to the development of a new branch of chemical industry, and to a large volume production of high-density and linear low-density polyethylene, isotactic polypropylene, ethylene-propylene rubbers, isotactic poly I-butene, and poly-4-methyl-l-pentene. These discoveries merited the Nobel prize, which was awarded to K. Ziegler and G. Natta in 1963. The initial works of Ziegler and Natta were followed by an "explosion" of scientific papers and patents covering all aspects of polymerization chemistry, catalyst synthesis, and polymerization kinetics as well as the structural, chemical, physical, and technological characteristics of stereo regular polyolefins, polydienes, and olefin copolymers. It is sufficient to say that in the twenty-five years after the first publications more than 15,000 papers and patents appeared on subjects related to the area. . The development brought about the establishment of several prominent groups of scientists occupied with the study of olefin polymerization. The most important of these were scientific schools in Italy, Germany, England, the United States, Japan, the Soviet Union, Czechoslovakia, and Venezuela. In addition, many major chemical and petrochemical corporations throughout the world established labora tories devoted to the development of the technology of catalyst synthesis and olefin polymerization.

With an enormous velocity, olefin polymerization has expanded to one of the most significant fields in polymers since the first industrial use about 50 years ago. In 2005, 100 million tons of polyolefins were produced - the biggest part was catalyzed by metallorganic compounds. The Hamburg Macromolecular Symposium 2005 with the title "Olefin Polymerization" involved topics such as new catalysts and cocatalysts, kinetics, mechanism and polymer reaction engineering, synthesis of special polymers, and characterization of polyolefins. The conference combined scientists from different disciplines to discuss latest research results of polymers and to offer each other the possibility of cooperation. This is reflected in this volume, which contains invited lectures and selected posters presented at the symposium.

Olefin metathesis reaction can be considered as one of the most successful organic reactions with many applications in the low molecular weight range and also in the polymer field. The use of catalysts with their selective and effective transformation properties in olefin metathesis I polymerization systems is a growing interest. There has been great effort and competition in developing active and commercially useful catalysts. The main aim of this ASI was to gather several research groups and also the people from industry. to present existing knowledge and latest results in the field. A wide range of topics through homogeneous and heterogeneous aspects have been considered. Attention has been drawn to the metal-carbene and metallacyclobutane complexes as active species, the initiation mechanisms, the stereochemistry and thermodynamics of these reactions. New catalytic systems for the metathesis of alkenes and alkynes and fot' ring opening polymeriZation I block copolymerization reactions have been introduced. Spectroscopic studies for the characteriZation of catalysts, simulation studies explaining the function of chain carrier species and polymer degradation have also been covered. A detailed industrial report concerning the patents and applications in olefin metathesis I cyc1001efin polymerization area, fabrication and derivation has been presented. This volume contains the main lectures and seminars given at the NATO Advanced Study Institute on " Olefin Metathesis and Polymerization Catalysts: Synthesis, Mechanism and Utilization", held at Akcay. Babkesir. Turkey between 10th and 22nd September 1989.