Download or read book Controlling Polymer Microstructure Using Multiblock Copolymers Via Reversible Addition fragmentation Chain Transfer Polymerization written by Junliang Zhang (Researcher in chemistry) and published by . This book was released on 2017 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development and Investigation of Externally Controlled Polymerizations written by Michael Joseph Supej and published by . This book was released on 2020 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Controlled polymerization methodologies have been pivotal to the development of advanced polymeric materials. These methodologies take advantage of chain-growth polymerization mechanisms wherein each initiating species theoretically generates a single growing polymer chain-this leads to tunable polymer molecular weights (Mns) and molecular weight distributions (dispersity, _), and thus supports the synthesis of novel, designer materials. Despite major advancements in controlled polymerization methods, there is still significant difficulty in generating materials with highly regular structures in a controlled manner without the need for challenging multistep syntheses that often require several isolations, purifications, and chain-end modifications before the final polymer material is acquired. To overcome this challenge, we sought to explore externally controlled polymerizations as they are uniquely positioned to generate complex polymer structures and architectures due to the inherent spatiotemporal control they provide over the polymerization (Chapter 1). An in-depth mechanistic analysis of photocontrolled cationic reversible addition-fragmentation chain transfer (RAFT) polymerization was performed to gain a better understanding of the stimuli controlled polymerizations (Chapter 2). Using the mechanistic insight gained during this previous study, we sought to improve upon the previously developed photocontrolled cationic RAFT polymerization by generating efficient photocatalysts which achieve greater temporal control and extending this chemistry toward polymer chain-end modification (Chapter 3). To enable the synthesis of multiblock copolymers through a facile process, a new chemically controlled cationic polymerization was developed and paired with an orthogonal photocontrolled radical polymerization, affording the synthesis of multiblock copolymers in a one-pot process (Chapter 4). Following this, a new electrochemically controlled cationic polymerization mediated by ferrocene was developed; this process was compatibilized with a photochemically controlled radical polymerization to facilitate the in situ synthesis of higher-order multiblock copolymers than were previously achievable by similar methodologies (Chapter 5). We then sought to develop a novel set of redox controlled acids and demonstrated that large changes in acidity occur upon oxidation, thus facilitating the polymerization of cyclic monomers (Chapter 6).
Download or read book Living and Controlled Polymerization written by Joseph Jagur-Grodzinski and published by Nova Publishers. This book was released on 2006 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: The living/controlled polymerisation techniques opened new vistas in polymer chemistry. The leading authorities in this field and its pioneers contributed chapters to this collective volume. The controlled polymerisation techniques have enabled preparation of polymers, copolymers, and block copolymers with predetermined molecular weights and narrow polydispersity, in which functional groups or biologically active molecules could be placed at well defined locations. They have also enabled preparation of advanced polymeric structures with precisely determined architectures and improved properties. Moreover, they have provided opportunities for preparation of novel polymeric materials from monomers, which before have not been suitable or accessible for such purposes. Properties of some of these polymeric materials may be significantly different from those of the existing ones. They provide opportunities for new applications. Several patents have already been approved for such speciality applications as, drug delivery, biocompatible surfaces, thermoplastic elastomers, moisture curable sealants, and so on. Many more products, based on polymers fabricated by the living/ controlled polymerisation techniques, will certainly emerge in such specialised areas as, nanotechnology, medical devices, "smart polymers", sensors , smart separation technologies, optical fibres and other optical applications, various biomaterials, etc.
Download or read book Synthesis of Novel Ion conducting Polymers Via Reversible Addition fragmentation Chain Transfer Polymerization written by Kyle C. Bryson and published by . This book was released on 2010 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent work in the Hickner research group has focused on creating novel, welldefined, ion-containing block copolymers for studies relating macromolecular chemistry, architecture, and resulting microphase-separated morphology to the transport properties of bulk films, such as ion-conductivity and water uptake, for application in polymer membranes for water salinity management and Polymer Electrolyte Membrane Fuel Cells (PEMFCs). Reversible addition fragmentation chain transfer (RAFT) polymerization, a controlled free radical polymerization technique, was used to synthesize homopolymers and block copolymers of styrene and vinylbenzyl chloride (VBC), a versatile vinylic monomer that serves as a platform onto which a wide array of ionic moieties may be attached. Synthesis of both a monofunctional (grown from one end) and a difunctional (grown from two ends) RAFT chain transfer agent was successful. Many attempts at difunctional, monofunctional, and chain extension RAFT polymerization of styrene and VBC yielded knowledge of experimental conditions most conducive to molecular weight control. Difunctional RAFT polymerization poses particular obstacles related to the unwanted creation of monofunctionalized polymer chains. Styrene polymerizations proceeded with more control than VBC polymerizations.
Download or read book Novel Stimuli responsive Block Copolymers Via Reversible Addition fragmentation Chain Transfer Polymerization written by Brent Sterling Sumerlin and published by . This book was released on 2003 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Statistical Gradient Block and Graft Copolymers by Controlled Living Radical Polymerizations written by Kelly A. Davis and published by Springer Science & Business Media. This book was released on 2007-11-02 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design and the realisation of well defined polymer architectures has become an important goal in macromolecular science. The prerequisite for achieving this goal is the availability of controlled polymerisation reactions. Living anionic polymerisation was the first reaction fulfilling these requirements. Cationic polymerisation only came into play when it was realised that it was possible to create an equilibrium between active and dormant species with the fraction of the dormant species being far superior to that of active ones. A corresponding principle applies to controlled radical polymerisation per formed in quite a number of modes such as nitroxide mediated polymerisation (NMP), atom transfer radical polymerisation (ATRP), reversible addition frag mentation chain transfer (RAFT) or catalytic chain transfer (CCT) reactions. All of these variants of controlled radical polymerisation lead to well defined archi tectures with the particular advantage that a much larger number of monomers are suitable and the reaction conditions are much less demanding than those of living ionic polymerisation reactions. Although in controlled radical polymerisation, termination reactions cannot be excluded completely, they are limited in their extent and consequently the mol ecular weight is controlled, the polydispersity index is small and functionalities can be attached to the macromolecules. These features are indicative of the real isation of well defined polymer architectures such as block copolymers, star shaped and comb shaped copolymers.
Download or read book Controlled Free Radical Polymerization in Miniemulsion Using Reversible Addition Fragmentation Chain Transfer RAFT written by Johannes Jacobus Vosloo and published by . This book was released on 2001 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Amino Functional Monomers Via Controlled Radical Polymerization written by Xeniya Savelyeva and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Controlled radical polymerization (CRP) techniques has allowed the synthesis of numerous polymeric materials with comparable control to that of true "living" techniques without the need for stringent manipulation techniques. The control over chain length, dispersity and composition is desirable in many fields, such as stimuli-responsive (temperature or pH) drug carriers. These thermoresponsive polymers in aqueous media are often characterized by lower critical solution temperature (LCST) behavior, where the polymer becomes insoluble with temperature increases. The LCST can be tuned by the structural features of the constituent monomer, molecular weight, molecular weight distribution and copolymerization with other monomers. Narrow molecular weight distribution is the key factor determining the sharpness needed for determining the LCST, which is often exemplified by the cloud point temperature (CPT). Using CRP techniques, specifically nitroxide mediated polymerization (NMP), with an alkoxyamine unimolecular initiator, 2-([tert-butyl[1-(diethoxyphosphoryl)-2,2-dimethylpropyl]amino]oxy)-2-methylpropanoic acid (BlocBuilder) and an additional free nitroxide (SG1), the effect of controlling comonomer (9-(4-vinylbenzyl)-9H-carbazole (VBK)) on polymerization kinetics of N-(2-methacryloyloxyethyl) pyrrolidone (MAEPYR) and the effect of final copolymer composition on CPT was studied. Adding at least 5 mol% VBK, the dispersity Đ of the poly(MAEPYR-stat-VBK) copolymers was below 1.4. The CPT decreased from 59.0 °C to 49.7 °C with addition of only 1 mol% of VBK in the copolymer, and it can be further fine-tuned by changing the solution concentration and the heating rate. Another CRP technique, reversible addition fragmentation chain-transfer polymerization (RAFT), was applied to homopolymerization of N-(3-methoxypropyl) acrylamide (MPAM) to yield well-defined polymers (with (M_n)− = 14.3 - 25.2 kg mol-1 and low Đ ~ 1.17 - 1.47) needed for precise determination of CPT. Thermoresponsive behaviour of poly(MPAM) in aqueous media revealed CPTs between 73 and 92 °C, unlike other literature reports where the polymers, synthesized by conventional radical polymerization, showed conflicting results regarding their LCST" --
Download or read book Handbook of Polymer Synthesis Characterization and Processing written by Enrique Saldivar-Guerra and published by John Wiley & Sons. This book was released on 2013-03-04 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering a broad range of polymer science topics, Handbook of Polymer Synthesis, Characterization, and Processing provides polymer industry professionals and researchers in polymer science and technology with a single, comprehensive handbook summarizing all aspects involved in the polymer production chain. The handbook focuses on industrially important polymers, analytical techniques, and formulation methods, with chapters covering step-growth, radical, and co-polymerization, crosslinking and grafting, reaction engineering, advanced technology applications, including conjugated, dendritic, and nanomaterial polymers and emulsions, and characterization methods, including spectroscopy, light scattering, and microscopy.
Download or read book Aqueous Reversible Addition fragmentation Chain Transfer Polymerization of Functional Monomers and Their Incorporation Into Stimuli responsive Amphiphilic Block Copolymers written by Bradley Steward Lokitz and published by . This book was released on 2007 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Controlled and Living Polymerizations written by Krzysztof Matyjaszewski and published by John Wiley & Sons. This book was released on 2009-09-28 with total page 640 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 The Synthesis of Well Defined Functional Homo and Block Copolymers in Aqueous Media Via Reversible Addition Fragmentation Chain Transfer RAFT Polymerization written by Murat Mertoğlu and published by . This book was released on 2005 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Functional and Complex Polymer Architectures written by Derek Lee Patton and published by . This book was released on 2006 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reversible Deactivation Radical Polymerization written by Nikhil K. Singha and published by Walter de Gruyter GmbH & Co KG. This book was released on 2020-01-20 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes strategies and mechanism of reversible deactivation radical polymerization (RDRP) to synthesize functional polymers. Several approaches such as atom transfer radical polymerization and the combination of click chemistry and RDRP are summarized. Contributors from interdisciplinary fields highlight applications in nanotechnology, self-healing materials, oil and water resistant coatings and controlled drug delivery systems.
Download or read book Kirk Othmer Concise Encyclopedia of Chemical Technology 2 Volume Set written by Kirk-Othmer and published by John Wiley & Sons. This book was released on 2007-07-16 with total page 2762 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an easily-accessible two-volume encyclopedia summarizing all the articles in the main volumes Kirk-Othmer Encyclopedia of Chemical Technology, Fifth Edition organized alphabetically. Written by prominent scholars from industry, academia, and research institutions, the Encyclopedia presents a wide scope of articles on chemical substances, properties, manufacturing, and uses; on industrial processes, unit operations in chemical engineering; and on fundamentals and scientific subjects related to the field.
Download or read book Handbook of Radical Polymerization written by Krzysztof Matyjaszewski and published by John Wiley & Sons. This book was released on 2003-04-14 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt: Klassische und moderne Verfahren der radikalischen Polymerisation: In diesem handlichen Band finden Sie Antworten auf theoretische und praktische Fragen. Neben grundlegenden Ausführungen zur Einteilung radikalischer Polymere sind Angaben über die wichtigsten experimentellen Verfahren zur Synthese, Reinigung und Charakterisierung von Polymeren enthalten. Interessante Zugabe: ein Abriß der Geschichte der Radikalkettenpolymerisation.
Download or read book Microstructure and Chain Conformation in Multiblock Copolymers written by John Anthony Miller and published by . This book was released on 1985 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt:
