Design of cobalt(III) carboxylate complexes for switching between radical and ring opening polymerization mechanisms

Design of cobalt(III) carboxylate complexes for switching between radical and ring opening polymerization mechanisms
Title Design of cobalt(III) carboxylate complexes for switching between radical and ring opening polymerization mechanisms PDF eBook
Author Maxime Michelas
Publisher
Pages 0
Release 2023
Genre
ISBN

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Dans le monde entier, les matériaux polymères prennent une grande place et remplacent bons nombres de matériaux traditionnels tels que le bois, l'acier ou le verre. En effet, ces polymères ont apporté une large gamme de propriétés intéressantes utiles à la vie de l'Homme comme celle de barrière aux gaz pour les emballages alimentaires, ou encore, permettent la constitution de matériaux légers pour l'automobile, réduisant ainsi les émissions de CO2. De plus, les besoins en polymères bien définis avec un control sur l'architecture (c-à-d. masse molaire, dispersité contrôlée, ou des bouts de chaines fonctionnalisés) ne cessent d'augmenter avec le temps pour de nouveaux matériaux de hautes performances. Néanmoins, en raison de l'émergence des problèmes environnementaux et des pressions sociétales, l'amélioration de nos matériaux usuels s'inscrit dans une stratégie de développement durable visant à remplacer ceux issus de la pétrochimie par des matériaux biosourcés et/ou biodégradables. C'est dans cette optique que s'inscrit notre recherche, qui consiste à utiliser des métaux abondants, peu coûteux et moins toxiques que les catalyseurs métalliques déjà utilisés pour la production industrielle de polymères. Les objectifs de ce projet visent ainsi à développer un composé de coordination à base de cobalt, qui servira d'amorceur et de modérateur pour deux types de polymérisations différentes : la polymérisation par ouverture de cycle (ROP) et la polymérisation radicalaire à médiation organométallique (OMRP). De plus, ce nouvel outil fonctionnerait sans aucun co-agent pour l'amorçage et le contrôle de ces polymérisations. Ces travaux de thèse s'articuleront avec différentes architectures autour du centre métallique : Des ligands à base de (N2,O2)- ou entièrement oxygénés et le fragment amorceur avec la structure carboxylate (Co-O(O)R). Et se divisera notamment en trois parties, la première sur l'OMRP, qui est basée sur un mécanisme radicalaire. Un catalyseur au degré d'oxydation X+1 capable d'effectuer le clivage homolytique par activation thermique et de générer un radical primaire oxygéné pour l'amorçage directe des monomères vinyliques (Vac, MA, S, ...). Et aussi, de libérer dans le milieu le métal à l'état d'oxydation X, qui joue le rôle de modérateur en piégeant de manière réversible la chaîne polymère en croissance. Ainsi, nous verrons la capacité du cobalt-carboxylate pour le clivage homolytique et le contrôle de la polymérisation des monomères MAM ou LAM, respectivement avec les types de ligands (N2,O2)- et entièrement Oxygénés. Par la suite la deuxième amènera la discussion sur les polymères biosourcés et biodégradables produit par ROP d'esters cycliques, notamment pour les monomères l-lactide (LA) ou Ɛ-caprolactone (CL), nous proposons que la même espèce cobalt-carboxylate puisse permettre la formation d'un nucléophile, en raison de la plus grande polarisabilité de la liaison Mt-Oxygène par rapport à la liaison Mt-Carbone. Et permettre l'attaque nucléophile de la fonction carbonyle du monomère. Par conséquent, un composé unique sera mis en évidence, qui peut fournir un radical et un nucléophile en fonction des conditions expérimentales et du type de monomères, pour amorcer et contrôler la polymérisation des monomères vinyliques et d'esters cycliques sans aucune modification chimique. L'idée sous-jacente est de synthétiser des copolymères à bloc en couplant des monomères non-biodégradables (ex : VAc, MA, S) et biodégradables (LA, CL), avec un mécanisme de commutation de polymérisation de OMRP à ROP. Et, sans aucune modification chimique entre chaque bloc. De façon plus large et appliquée, ces travaux visent à découvrir et maîtriser de nouvelles voies de synthèse de matériaux aux propriétés biodégradables.

Olefin Polymerization

Olefin Polymerization
Title Olefin Polymerization PDF eBook
Author Walter Kaminsky
Publisher Wiley-VCH
Pages 0
Release 2006-08-18
Genre Technology & Engineering
ISBN 9783527317424

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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.

Bioinorganic Photochemistry

Bioinorganic Photochemistry
Title Bioinorganic Photochemistry PDF eBook
Author Grazyna Stochel
Publisher John Wiley & Sons
Pages 398
Release 2009-06-10
Genre Science
ISBN 9781405193276

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Bioinorganic photochemistry is a rapidly evolving field integrating inorganic photochemistry with biological, medical and environmental sciences. The interactions of light with inorganic species in natural systems, and the applications in artificial systems of medical or environmental importance, form the basis of this challenging inter-disciplinary research area. Bioinorganic Photochemistry provides a comprehensive overview of the concepts and reactions fundamental to the field, illustrating important applications in biological, medical and environmental sciences. Topics covered include: Cosmic and environmental photochemistry Photochemistry of biologically relevant nanoassemblies Molecular aspects of photosynthesis Photoinduced electron transfer in biosystems Modern therapeutic strategies in photomedicine The book concludes with an outlook for the future of environmental protection, discussing emerging techniques in the field of pollution abatement, and the potential for bioinorganic photochemistry as a pathway to developing cheap, environmentally friendly sources of energy. Written as an authoritative guide for researchers involved in the development of bioinorganic photochemical processes, Bioinorganic Photochemistry is also accessible to scientists new to the field, and will be a key reference source for advanced courses in inorganic, and bioinorganic chemistry.

Comprehensive Coordination Chemistry II

Comprehensive Coordination Chemistry II
Title Comprehensive Coordination Chemistry II PDF eBook
Author J. A. McCleverty
Publisher Newnes
Pages 11845
Release 2003-12-03
Genre Science
ISBN 0080913164

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Comprehensive Coordination Chemistry II (CCC II) is the sequel to what has become a classic in the field, Comprehensive Coordination Chemistry, published in 1987. CCC II builds on the first and surveys new developments authoritatively in over 200 newly comissioned chapters, with an emphasis on current trends in biology, materials science and other areas of contemporary scientific interest.

Alternating Copolymers

Alternating Copolymers
Title Alternating Copolymers PDF eBook
Author J.M.G. Cowie
Publisher Springer Science & Business Media
Pages 292
Release 2013-06-29
Genre Technology & Engineering
ISBN 1475791399

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Examination of the early literature attests to the fact that the study of copolymerization was initiated when polymer science was in its infancy. It has continued to grow to a subject of major importance and has been a source of interest to both academic and industrialist alike. The wide spectrum of structures and properties available in the statistical copolymer has made this a fruitful field of exploration, but one particular and more restricted form which has held its own fascination for many is the limiting case of the strictly alternating copolymer. This is formed, in the ideal situation, when two monomers in a reaction mixture add consecutively to create a polymer chain with a regular {ABABAB} structure, irrespective of the monomer feed ratio. When this happens the resulting copolymer will always have the same composition, a feature which can be advantageous but also somewhat restrictive, as the ability to vary the properties is then limited. Within a series entitled Speciality Polymers it seems appropriate then to deal with this subject, particularly as no previous attempt has been made to draw together the various facets of alternating copolymerization into one volume. It also seems timely to present a more unified picture of the subject which will also illustrate the progress made.

Synthetic Biodegradable Polymers

Synthetic Biodegradable Polymers
Title Synthetic Biodegradable Polymers PDF eBook
Author Bernhard Rieger
Publisher Springer
Pages 0
Release 2014-02-22
Genre Technology & Engineering
ISBN 9783642436871

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Salen Metal Complexes as Catalysts for the Synthesis of Polycarbonates from Cyclic Ethers and Carbon Dioxide, by Donald J. Darensbourg.- Material Properties of Poly(Propylene Carbonates), by Gerrit. A. Luinstra and Endres Borchardt.- Poly(3-Hydroxybutyrate) from Carbon Monoxide, by Robert Reichardt and Bernhard Rieger. - Ecoflex® and Ecovio®: Biodegradable, Performance-Enabling Plastics, by K. O. Siegenthaler, A. Künkel, G. Skupin and M. Yamamoto.- Biodegradability of Poly(Vinyl Acetate) and Related Polymers, by Manfred Amann and Oliver Minge.- Recent Developments in Ring-Opening Polymerization of Lactones, by P. Lecomte and C. Jérôme.- Recent Developments in Metal-Catalyzed Ring-Opening Polymerization of Lactides and Glycolides: Preparation of Polylactides, Polyglycolide, and Poly(lactide-co-glycolide), by Saikat Dutta, Wen-Chou Hung, Bor-Hunn Huang and Chu-Chieh Lin.- Bionolle (Polybutylenesuccinate), by Yasushi Ichikawa, Tatsuya Mizukoshi.- Polyurethanes from Renewable Resources, by David A. Babb.-

Cage Metal Complexes

Cage Metal Complexes
Title Cage Metal Complexes PDF eBook
Author Yan Voloshin
Publisher Springer
Pages 475
Release 2017-05-11
Genre Science
ISBN 331956420X

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This fundamental book presents the most comprehensive summary of the current state in chemistry of cage metal complexes. After their previous book “The Encapsulation Phenomenon” (www.springer.com/978-3-319-27737-0) the authors in this book focus on the encapsulation of metal ions by different types of three-dimensional mono- and polynucleating caging ligands. Within these cage metal complexes, (metal) ions can be isolated from external factors. The book provides both a classification of the cage compounds and summaries of synthetic approaches. On that basis the authors then describe the unique chemical and physical properties and the resulting reactivity of the cage compounds, as well as practical and potential applications as potent topological drugs and prodrugs, antifibrillogenic agents, radiodiagnostic and radiotherapeutic compounds, paramagnetic probes, single-molecule magnets, electrocatalysts for hydrogen production, (photo)electronic devices, and many more. Readers will find a well-structured and concise overview, with particular emphasis on a review of synthesis and reactivity of various cage metal complexes, summarizing over 400 literature references, clearly presented in over 300 color schemes and figures.