Download or read book Living Stereoselective Olefin Polymerizations Using Titanium Bis phenoxyimine Catalysts written by Andrew Felix Mason and published by . This book was released on 2006 with total page 644 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 Development of Functionalized Polymers Using Bis phenoxyimine titanium and alpha diimineNickel II Catalysts for the Production of New Polyolefin Architectures written by Amelia Marie Anderson and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Decades of research in the area of metal-catalyzed olefin polymerization, since the initial discoveries by Ziegler and Natta in the 1950s, has lead to the development of a wide variety of transition metal catalysts as well as numerous polymer architectures. Although early work in the field focused on heterogeneous catalysis, Kaminsky's discovery of the scavenger/activator methylaluminoxane in 1980 facilitated a renaissance in the area of homogeneous catalysts. Today, many commercial polyolefin materials are still limited to linear homopolymers, random copolymers, or blends thereof. Therefore, our efforts have focused on the endfunctionalization and random incorporation of polar functional groups into polyolefins to produce polymers with improved properties and more complex architectures than traditional linear polymers. Initial work in this area focused on the development of well-defined long-chain branched polymers from end-functionalized polypropylene. Although many star polymers have been produced using anionic, cationic and radical methods, semicrystalline polypropylene materials with similar structures from coordinationinsertion polymerization were not known. Using a non-living bis(phenoxyimine)titanium catalyst, allyl-terminated syndiotactic polypropylene was produced and utilized in the production of alcohol-, azide- and amine-terminated polymers. These end-functionalized macromolecules were employed in the synthesis of a variety of well-defined branched polymers including star, miktoarm star and H- polymers. In an effort to produce branched polyolefin materials with high molecular weight, a norbornene-terminated polymer was synthesized from the allyl-terminated syndiotactic polypropylene. Using ring-opening metathesis polymerization, a number of high molecular weight polypropylene comb polymers were produced. All of the branched, syndiotactic polypropylene materials were analyzed further in an effort to related branching with observed polymer properties. To produce polyolefins with improved properties, a series of random copolymers derived from propylene and a polar, hydrogen bonding monomer were produced using Ni(II) [alpha]-diiminecatalysts. By varying the reaction temperature, hydrogen bonding polypropylene materials with a range of microstructures were produced. At high reaction temperatures, regioirregular, amorphous polypropylene was obtained, whereas, decreasing reaction temperature lead to highly regioregular, isotactic polypropylene. Utilizing the living nature of the Ni(II) [alpha]-diiminecatalysts, a series of triblock copolymers containing hydrogen bonding moieties in the midblock were also produced. The mechanical properties of all materials were investigated and generally observed to improve upon incorporation of small amounts (~1%) of the ureidopyrimidinone. For the branched and hydrogen bonding polymer reported herein, functionalization of polypropylene allowed for the synthesis of new polyolefin architectures.

Download or read book New Polyolefin Architectures Through the Development of Living and Stereoselective Group IV Phenoxyketimine and Phenoxyamine Olefin Polymerization Catalysts written by Joseph B Edson and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the pioneering work by Ziegler and Natta in the 1950s on metalcatalyzed olefin polymerization, decades of research have led to the development of catalysts capable of furnishing a wide variety of polymers. Early work focused on heterogeneous catalysts, but the later development of homogeneous catalysts provided mechanistic insights that have allowed researchers to develop catalysts that provide access and control over specific polymer microstructures. The majority of commercial polyolefins has traditionally been limited to homopolymers, random copolymers, or blends thereof. In the past decade however, the development of olefin polymerization catalysts that are living have now allowed access to virtually a limitless number of new polyolefin architectures. Despite the fact that a living polymerization system is capable of producing only one polymer chain per metal center, the real advantage lies in the ability to synthesize well-defined block copolymers and identify new materials with promising properties. Our efforts have focused on C2-symmetric bis(phenoxyketimine) titanium dichloride complexes and C1-symmetric phenoxyamine zirconium and hafnium dibenzyl complexes supported by an sp3-C donor. We have shown that upon activation, these complexes can catalyze the living and isoselective polymerization of !-olefins. Using these, the synthesis of a number of new block copolymers featuring semicrystalline isotactic polypropylene segments and amorphous poly(ethylene-co-propylene) segments was accomplished. The resultant block copolymers displayed elastomeric behavior and excellent mechanical properties. We have further shown that catalysts derived from the C1-symmetric phenoxyamine zirconium and hafnium dibenzyl complexes are capable of the cyclopolymerization of 1,5-hexadiene. The resultant polymers were shown to have a previously unreported cis-isotactic microstructure.

Download or read book Controlled and Living Polymerizations written by Krzysztof Matyjaszewski and published by John Wiley & Sons. This book was released on 2009-12-23 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by a highly prestigious and knowledgeable team of top scientists in the field, this book provides an overview of the current status of controlled/living polymerization, combining the synthetic, mechanistic and application-oriented aspects. From the contents: * Anionic Vinyl Polymerization * Carbocationic Polymerization * Radical Polymerization * Coordinative Polymerization of Olefins * Ring-Opening Polymerization of Heterocycles * Ring-Opening Metathesis Polymerization * Macromolecular Architectures * Complex Functional Macromolecules * Synthesis of Block and Graft Copolymers * Bulk and Solution Structures of Block Copolymers * Industrial Applications While some of the material is based on chapters taken from the four-volume work "Macromolecular Engineering", it is completely updated and rewritten to reflect the focus of this monograph. Must-have knowledge for polymer and organic chemists, plastics technologists, materials scientists and chemical engineers.

Download or read book Development of New Catalysts for Living Polymerizations written by Phillip Dene Hustad and published by . This book was released on 2002 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transition Metals and Organometallics as Catalysts for Olefin Polymerization written by Walter Kaminsky and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 443 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Novel Titanium IV Catalysts for Olefin Polymerization written by Saman Damavandi and published by LAP Lambert Academic Publishing. This book was released on 2013 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of olefin polymerization has been remarkably renewed with the use of metallocene and post metallocene catalyst. Novel transition-metal complexes were studied as catalysts in ethylene polymerization. The aim of this work is to investigate the feasibility of replacing the cyclopentadienyl ligands of metallocenes by bis(aminotropone) ligands as well as by new bis(imino)pyridinato ligands without losing the good properties of the metallocenes, such as high activity and formation of linear polymer. It was presumed that the polymerization mechanism and the active center in ethylene polymerization would be similar for iminopyridinato and metallocene catalysts. Titanium (IV) and nickel (II) catalysts based on bis(anilinotropone) ligands were prepared and their structures determined to clarify the relationship between structure of the catalyst precursor and polymerization results. In experimentation, the syntheses, structures and olefin polymerization behavior of Ti complexes containing a pair of chelating aminotropone [O-N] ligands are reported. DFT studies revealed that bis(aminotropone) Ti complexes, when activated, provide a metal alkyl in the cis position to a vacant coordina

Download or read book Beyond Metallocenes written by Abhimanyu O. Patil and published by . This book was released on 2003 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: The past 15 years have witnessed tremendous advances in the design and use of organometallic complexes as precatalysts for olefin polymerization. Most recently, an intense search has been started in next-generation single-site catalysts. New approaches have been taken to ligand design. This research has yielded extraordinary results such as catalysts with activities as high or higher than those of conventional metallocenes, stereospecific and living polymerizations, and amazing new polymer structures such as highly-branched ethylene homopolymers. This volume presents some of the recent disclosures in this exciting and rapidly expanding field, featuring papers by some of the leading investigators.

Download or read book Catalytic Olefin Polymerization written by T. Keii and published by Elsevier. This book was released on 1990-09-12 with total page 597 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent development of a new generation of Ziegler-Natta Catalysts using either magnesium dichloride as carrier or methylaluminoxane as cocatalyst has markedly stimulated the research activity in the field of olefin polymerization. These discoveries have not only yielded economical processes for polyolefin production but also opened the way to a new generation of novel polymers. Moreover, the nature of active species is being clarified well by the effort to simplify catalyst systems. The present volume includes 38 papers from the 31 lectures and 18 posters presented at the symposium on `Recent Developments in Olefin Polymerization Catalysts', which covered the following topics: Overview of super-active homogeneous and heterogeneous catalysts, kinetic profile of olefin polymerization including copolymerization, characterization of catalysts and polymers, methods for the determination of active center concentration, role of Lewis bases on the catalysts isospecificity, polymerization mechanisms, and synthetic pathways for functionalized polyolefins. The contents are well balanced between fundamental research and application as well as between homogeneous and heterogeneous catalyst systems.

Download or read book Monitoring Polymerization Reactions written by Wayne F. Reed and published by John Wiley & Sons. This book was released on 2014-01-21 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers new strategies to optimize polymer reactions With contributions from leading macromolecular scientists and engineers, this book provides a practical guide to polymerization monitoring. It enables laboratory researchers to optimize polymer reactions by providing them with a better understanding of the underlying reaction kinetics and mechanisms. Moreover, it opens the door to improved industrial-scale reactions, including enhanced product quality and reduced harmful emissions. Monitoring Polymerization Reactions begins with a review of the basic elements of polymer reactions and their kinetics, including an overview of stimuli-responsive polymers. Next, it explains why certain polymer and reaction characteristics need to be monitored. The book then explores a variety of practical topics, including: Principles and applications of important polymer characterization tools, such as light scattering, gel permeation chromatography, calorimetry, rheology, and spectroscopy Automatic continuous online monitoring of polymerization (ACOMP) reactions, a flexible platform that enables characterization tools to be employed simultaneously during reactions in order to obtain a complete record of multiple reaction features Modeling of polymerization reactions and numerical approaches Applications that optimize the manufacture of industrially important polymers Throughout the book, the authors provide step-by-step strategies for implementation. In addition, ample use of case studies helps readers understand the benefits of various monitoring strategies and approaches, enabling them to choose the best one to match their needs. As new stimuli-responsive and "intelligent" polymers continue to be developed, the ability to monitor reactions will become increasingly important. With this book as their guide, polymer scientists and engineers can take full advantage of the latest monitoring strategies to optimize reactions in both the lab and the manufacturing plant.

Download or read book Oligomerization and Polymerization of Ethylene by Phenoxy imine Titanium Catalysts written by Astrid Cordier and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1-hexene is one of the most important olefin used as comonomer for the production of value-added polyethylenes (HDPE, LLDPE). In the field of selective ethylene trimerization employing titanium-based catalysts, specific single tridentate phenoxy-imine complexes (SFI) display the highest activity and 1-hexene selectivity upon activation with methylaluminoxane (MAO). However, ethylene polymerization is an unavoidable side reaction affecting both 1-hexene selectivity and process operations. Although being a major drawback, the causes of polymerization remain a grey area since few studies were dedicated to its deciphering. To handle this challenge , an original “polymer-to-catalyst” strategy was implemented. An extensive temperature study (26-80°C) revealed that the highest 1-hexene activity is reached between 30 °C and 40 °C while polymer production is prominent above 50 °C. Polyethylenes obtained were analyzed by SEC, NMR DSC, and advanced segregation techniques (CEF, SIST, rheology). Molar masses above 10^5 g mol-1 were identified along with a 1-hexene content below 1 mol %. An increase of dispersity (Ɖ > 2) with temperature was ascribed to an evolution from single to multi-site polymerization catalysis. Kinetic studies proved that polymer is continuously produced even at short reaction time, for any reaction temperature. Other parameters (addition of 1-hexene, hydrogen and use of trimethylaluminum) were found to impair the trimerization selectivity and/or activity of the system. Nevertheless, it was possible to lower the selectivity in polyethylene by premixing the complex with MAO. After analyzing the possible routes for the polymerization catalyst formation, the hypotheses of temperature and MAO-induced complex alterations were considered. Regarding the latter, a molecular ligand-free Ziegler-Natta catalyst, modeled using TiCl4/MAO, and the synthesized (FI)Ti(III)Cl2 activated by MAO could not explain polymer production in the SFI system. Formation of a polymerization species upon thermal alteration of the SFI complex was evidenced. This [O-,N,O-]-type species displays common features regarding catalytic response to 1-hexene compared to the polymerization catalyst in the SFI system although it could not reach the same catalytic performances. The formation of a bis(phenoxy-imine) complex (FI)2TiCl2 was evidenced in this thesis and is a promising avenue worth exploring. Eventually, although the exact species has not yet been identified, this work enabled to guide the focus of further investigations on activation process and complex rearrangement by ligand mobility.

Download or read book Olefin Metathesis and Polymerization Catalysts written by Yavuz Imamogammalu and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 567 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Progress in Olefin Polymerization Catalysts and Polyolefin Materials written by Takeshi Shiono and published by Elsevier. This book was released on 2011-09-22 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: The First Asian Polyolefin Workshop introduces the recent developments and the research activities on polyolefin technology in Asia, which is becoming one of the important places in technology as well as in economy. Asian Countries have experienced remarkable economic growth in the last decade as represented by China. The Asian Polyolefin Workshop (APO) was planned to provide a venue for Asian scientists and engineers identifying and exploring the areas of common interests. The workshop was held in Nara on December 7th-9th, 2005, with more than 100 participants from China, Israel, India, Japan, Korea, Russia, Spain and Thailand. The following research topics were covered with 34 oral and 37 poster presentations; 1) Heterogeneous olefin polymerization catalysts Traditional Ziegler-Natta, Phillips, heterogenized metallocene and post metallocenes 2) Homogeneous olefin polymerization catalysts Traditional Ziegler-Natta, metallocene and post metallocenes 3) Precise synthesis of new polyolefins 4) Structure and properties of polyolefins 5) Engineering aspects of olefin polymerization * Presents the latest proceedings on polyolefin technology * The first book contributed by almost all the distinguished scientists in Asian countries* Contains papers not only from academia but also from industry

Download or read book Metallocenes in Regio and Stereoselective Synthesis written by Tamotsu Takahashi and published by Springer Science & Business Media. This book was released on 2005-01-12 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metallocene is a well known sandwich complex with two cyclopentadienyl ligands such as ferrocene. Recently, such metallocene compounds have been found to be very characteristic and they have become very important, not only in the area of organic synthesis, but also in polymerization in industry. Metal complexes with one cyclopentadienyl ligand have also become popular as half sandwich complexes. The number of researchers in the field of metallocenes has increased rapidly. However, the origin of the characteristic reactivity of metallocenes is not fully understood. In this volume, the chemistry of metal complexes with at least one cyclopentadienyl ligand is comprehensively covered by leading experts. Reactions discussed here are (i) natural product synthesis, (ii) catalytic asymmetric synthesis, (iii) cyclization reactions, (iv)catalytic reactions, (iv) polymerization reactions and (v) carbon-carbon bond cleavage reactions. The reader will have access to useful information about the current state of metallocene chemistry.

Download or read book Catalyst Design for Tailor Made Polyolefins written by M. Terano and published by Elsevier. This book was released on 1994-11-01 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent development of olefin polymerization catalysts has caused marked changes in both industrial and academic research. Industrial use of homogeneous metallocene catalysts has already begun in the fields of high density polyethylene and syndiotactic polypropylene. Moreover, important data have been obtained from academic investigations which have proved useful for understanding conventional heterogeneous Ziegler-Natta catalysts. From the industrial viewpoint, however, heterogeneous high-yield catalysts seem to be more important. The present volume contains invited lectures and contributed papers. The following topics are covered: (1) Heterogeneous Catalysts, (2) Metallocene Catalysts and (3) New Trends in the Polyolefin Industry.

Download or read book Organometallic Reactions and Polymerization written by Kohtaro Osakada and published by Springer. This book was released on 2014-07-15 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.