Download or read book Supported Aqueous phase Catalysis for Atom Transfer Radical Polymerization written by Ravi Aggarwal and published by . This book was released on 2010 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atom transfer radical polymerization (ATRP) which utilizes transition metal based catalysts is a versatile methodology for the synthesis of a wide spectrum of polymers with controlled architectures. However, high concentrations of soluble catalyst required in an ATRP process makes the final polymer colored and toxic. Thus, the catalyst removal/reduction/recycling remains a challenge in the field of ATRP. Supported catalysts on insoluble solids such as silica gel, polystyrene beads, etc. have been used in ATRP to facilitate the catalyst recovery and recycling. However, the ability of the supported catalysts to mediate a polymerization is substantially reduced due to their reduced mobility and leaching problems. In this thesis, we report a series of novel and recyclable physisorbed CuBr2/N, N, N', N'' -pentamethyldiethylene-triamine supported catalytic systems operating in conjunction with hydration. Supported aqueous-phase catalysis (SAPC) for ATRP was evaluated for different inorganic (Na-clay, silica and zeolite) and organic (polysaccharides) supports. The hydrated physisorbed supported catalysts were used for the polymerization of benzyl methacrylate and methyl methacrylate using an activator generated electron transfer ATRP process. The catalyst was effectively retained on the surface of supports through hydration as was verified by UV-Vis measurements. The supported catalyst was easily removed from the polymerization by simple filtration process affording a colorless polymer solution. The polymerizations produced high conversion and colorless polymers with moderately narrow polydispersity indices (PDI). The catalyst maintained high activity during the recycling experiments. We also investigated the kinetic and mechanistic behavior of these solid supported polymerization systems. Based on split kinetics experiments and UV-Vis studies it was believed that the activation and deactivation processes took place at the diffused hydrated interface between the solid support and organic phase. The branched (stars and graft) polymers were also synthesized using Na-clay supported catalyst. The produced polymers had narrow PDI and good initiator efficiencies. The functionality of the star polymers was confirmed using 1H NMR and dilute solution properties. The synthesis of graft-copolymer was confirmed by 1H NMR and atomic force microscopy. This thesis demonstrates the successful use of SAPC for ATRP to produce contamination free linear and branched polymers with moderately narrow PDI and high recycling efficiency.
Download or read book Indicators and Reagents Advances in Research and Application 2012 Edition written by and published by ScholarlyEditions. This book was released on 2012-12-26 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Indicators and Reagents—Advances in Research and Application: 2012 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Indicators and Reagents. The editors have built Indicators and Reagents—Advances in Research and Application: 2012 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Indicators and Reagents in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Indicators and Reagents—Advances in Research and Application: 2012 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Download or read book Handbook of Phase Transfer Catalysis written by Y. Sasson and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 579 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phase transfer catalysis is a sophisticated chemical technique which can be used to perform a variety of chemical reactions under mild conditions and with improved control. Since the concept was developed, both the theoretical and practical synthetic applications have seen considerable development, to the point where the technique can be applied to many areas of chemistry. Thus, phase transfer methods are now utilized in many applications, from research chemistry to full-scale production, where the benefits of faster, cleaner and more selective reactions are required. In this new book, the editors have brought together a range of contributors, each of whom is working at the forefront of the technology, to provide a clear, concise and ahtoritative review of this important area of chemistry. Industrial and academic chemists working on the synthesis, scale-up, production or analysis of a wide range of chemical products will find this book an essential reference on phase transfer technology.
Download or read book Phase Transfer Catalysis written by C.M. Starks and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since 1971 when useful working concepts for the technique of phase-transfer catalysis (PTC) were introduced, the understanding, development, and applica tions of this method for conducting organic reactions has expanded exponentially. PTC has brought vast new dimensions and options to chemists and chemical engineers. From its use in less than ten commercial processes in 1975, PTC use has increased so that in the early 1990s it is involved in more than 600 industrial applications to manufacture products valued at between 10 and 20 billion U.S. dollars. PTC is widely used for simple organic reactions, steps in synthesis of pharmaceuticals, agricultural chemicals, perfumes, ftavorants, and dyes; for specialty polymerization reactions, polymer modifications, and monomer synthe sis; for pollution and environmental control processes; for analysis oftrace organic and inorganic compounds; and for many other applications. Often, PTC offers the best (and sometimes only) practical technique to obtain certain products. The authors experience in teaching a short course on phase-transfer catalysis has shown to us that a newcomer to PTC can easily be frustrated and confused by the large amount of information available in the literature and in patents. The purpose of this book, therefore, was to bring this information together in a logical and user-friendly way, without sacrificing matters of scholarly and fundamental importance.
Download or read book Design Synthesis and Optimization of Recoverable and Recyclable Silica immobilized Atom Transfer Radical Polymerization Catalystal written by Joseph Vu Nguyen and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the growing interest in heterogeneous polymerization catalysis, the majority of the polymerization catalysts used industrially are single-use entities that are left in the polymer product. Recoverable and recyclable polymerization catalysts have not reached the industrial utility of single-use catalysts because the catalyst and product separation have not become economical. The successful development of recyclable transition metal polymerization catalysts must take a rational design approach, hence academic and industrial researchers need to further expand the fundamental science and engineering of recyclable polymerization catalysis to gain an understanding of critical parameters that allow for the design of economically viable, recoverable solid polymerization catalysts. Unfortunately, the rapid development of Atom Transfer Radical Polymerization over the past 10 years has not resulted in its wide spread industrial practice. Numerous reports regarding the immobilization of transition metal ATRP catalysts, in attempts to increase its applicability, have extended the fundamentals of recyclable polymerization catalysis. However, for industrial viability, more research is required in the area of how the catalyst complex immobilization methodology and support structure affect the catalyst polymerization performance, regeneration, and recyclability. A comprehensive rational catalyst design approach of silica-immobilized ATRP catalyst was undertaken to answer these questions and are discussed here.
Download or read book Crown Ethers and Phase Transfer Catalysis in Polymer Science written by Lon Mathias and published by Springer Science & Business Media. This book was released on 2013-11-22 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phase transfer catalysis or interfacial catalysis is a syn thetic technique involving transport of an organic or inorganic salt from a solid or aqueous phase into an organic liquid where reaction with an organic-soluble substrate takes place. Over the past 15 years there has been an enormous amount of effort invested in the development of this technique in organic synthe sis. Several books and numerous review articles have appeared summarizing applications in which low molecular weight catalysts are employed. These generally include either crown ethers or onium salts of various kinds. While the term phase transfer catalysis is relatively new, the concept of using a phasetrans fer agent (PTA) is much older~ Both Schnell and Morgan employed such catalysts in synthesis of polymeric species in the early 1950's. Present developments are really extensions of these early applications. It has only been within the last several years that the use of phase transfer processes have been employed in polymer synthesis and modification. Similarly, the use of polymer-bound phase transfer agents is also a recent development. These and related areas have nonetheless enjoyed explosive growth as mea sured by the number of publications and the variety of applica tions which have appeared. Several reviews dealing with these l 6 polymer-related investigations have been published.
Download or read book Metal Catalyzed Polymerization written by Samir Chikkali and published by CRC Press. This book was released on 2017-08-03 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proposed book focusses on metal mediated/catalyzed “controlled/living radical polymerization” (CRP/LRP) methods. It surveys a wide variety of catalyzed polymerization reactions, making it essentially a “one stop” review in the field. A significant contribution to polymer science is “metathesis polymerization” discovered by Grubbs and others. The book will cover various metathesis polymerization methods and implications in polymer industry.
Download or read book Recoverable and Recyclable Catalysts written by Maurizio Benaglia and published by John Wiley & Sons. This book was released on 2009-08-31 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recoverable and Recyclable Catalysts There is continued pressure on chemical and pharmaceutical industries to reduce chemical waste and improve the selectivity and efficiency of synthetic processes. The need to implement green chemistry principles is a driving force towards the development of recoverable and recyclable catalysts. The design and synthesis of recoverable catalysts is a highly challenging interdisciplinary field combining chemistry, materials science engineering with economic and environmental objectives. Drawing on international research and highlighting recent developments, this book serves as a practical guide for both experts and newcomers to the field. Topics covered include: An introduction to the principles of catalyst recovery and recycling Catalysts on insoluble and soluble support materials Thermomorphic catalysts, self-supported catalysts and perfluorous catalytic systems The development of reusable organic catalysts Continuous flow and membrane reactors Each chapter combines principles with practical information on the synthesis of catalysts and strategies for catalyst recovery. The book concludes with a comparison of different catalytic systems, using case studies to illustrate the key features of each approach. Recoverable and Recyclable Catalysts is a valuable reference source for academic researchers and professionals from a range of pharmaceutical and chemical industries, particularly those working in catalysis, organic synthesis and sustainable chemistry.
Download or read book Copper I Catalyzed Atom Transfer Radical Polymerization written by Amy Theresa Thomas and published by . This book was released on 2000 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymer Particles written by Masayoshi Okubo and published by Springer Science & Business Media. This book was released on 2005-02-10 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this special volume on polymer particles, recent trends and developments in the synthesis of nano- to micron-sized polymer particles by radical polymerization (Emulsion, Miniemulsion, Microemulsion, and Dispersion Polymerizations) of vinyl monomers in environmentally friendly heterogeneous aqueous and supercritical carbon dioxide fluid media are reviewed by prominent worldwide researchers. In addition to the important challenges and possibilities with regards to design and preparation of functionalized polymer particles of controlled size, the topics described are of great current interest due to the increased awareness of environmental issues.
Download or read book Supported Aqueous Phase Catalysis written by Juan Pedro Arhancet and published by . This book was released on 1989 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Living Radical Polymerization in Aqueous Dispersed Systems with Water Soluble Catalysts written by and published by . This book was released on 2015 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Living radical polymerization is an important technique for synthesizing advanced macromolecules including block copolymers. Since its discovery in the early 1990s the capability of the field has expanded with new types of chemistry and techniques. One of the most widely used chemistries is atom transfer radical polymerization (ATRP) also known as "metal mediated living radical polymerization" (Mt-LRP). Mt-LRP has also expanded its use to aqueous dispersed systems including emulsion, miniemulsion and microemulsion, with the biggest advancements seen in miniemulsion where the droplets act as nanosized reactors. Extremely hydrophobic catalyst complexes are typically used in miniemulsion. While effective in controlling the polymerization, these hydrophobic catalyst complexes also get trapped in the final polymer particles and are difficult to remove. Herein I report the progress made using thermoresponsive polymer bound catalysts for Mt-LRP reactions in miniemulsion, which allow the successful LRP in miniemulsion with facile catalyst removal. Polymers could be prepared with less than 10 ppm of ruthenium in the final polymer compared to >500 ppm in the reaction mixture. The polymerizations were improved by the addition of ferrocene (FeCp2) in miniemulsion, to give almost complete conversion in significantly shorter times. The addition of ferrocene adds a second catalytic cycle that is ionic in nature and requires excess halogens present for a successful polymerization to occur. The ionic species in this catalytic cycle meant that the use of cationic surfactants with halogen counter-ions could directly affect the polymerization chemistry, which was shown by increasing rates with the addition of a bromine counter-ion versus a chlorine counter ion in the cationic surfactant used. Water-soluble FeCp2 derivative cocatalysts were also used to improve the rates and conversions of Mt-LRP of ruthenium catalyzed polymerizations while also allowing colourless polymers to be synthesized. Finally, the ligand EHA6TREN, was found to be active in bulk or solution (anisole) when complexed to iron (III) bromide with reverse ATRP, or to iron (II) bromide with AGET ATRP, yielding an iron-mediated living radical polymerization.
Download or read book Science and Technology in Catalysis written by Masakazu Anpo and published by Gulf Professional Publishing. This book was released on 2003-07-09 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Selected) -- Plenary Lecures: New Catalysts for Controlled/Living Atom Transfer Radical Polymerization (ATRP; Catalysis and Applications of Gold Nanoparticles -- Oral Presentations: Ionic Liquids as New Solvents and Catalysis for Petrochemical and Refining Processes; High Throughput Experiment on the Investigation of Oxidation Catalysts with Gas Sensor System -- Poster Presentations: Development of a Low-Temperature Dioxin Decomposition Catalyst; Studies on Unique Properties of Polyolefins Prepared with Metallocene Catalyst Systems -- Index.
Download or read book Organic Inorganic Hybrid Nanomaterials written by Susheel Kalia and published by Springer. This book was released on 2014-12-04 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Polymer Science enjoys a longstanding tradition and good reputation in its community. Each volume is dedicated to a current topic, and each review critically surveys one aspect of that topic, to place it within the context of the volume. The volumes typically summarize the significant developments of the last 5 to 10 years and discuss them critically, presenting selected examples, explaining and illustrating the important principles, and bringing together many important references of primary literature. On that basis, future research directions in the area can be discussed. Advances in Polymer Science volumes thus are important references for every polymer scientist, as well as for other scientists interested in polymer science - as an introduction to a neighboring field, or as a compilation of detailed information for the specialist.
Download or read book Cu and Fe mediated Atom transfer Radical Polymerization in Aqueous Solution written by Sebastian Smolne and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanism and the kinetics of metal-catalyzed radical polymerization were investigated by spectroscopic methods and by PREDICI® simulation. A particular focus was on Cu- and Fe-mediated atom-transfer radical polymerization (ATRP) in aqueous solution of poly(ethylene glycol)ether methacrylate (PEGMA) and on monomer-free model systems. The propagation kinetics of PEGMA in aqueous solution were determined between 20 and 77 °C via PLP-SEC. The significant dependence of kp on monomer content is due to the difference in the degree by which internal rotations of the transition state for propag...
Download or read book Phase Transfer Catalysis written by Eckehard V. Dehmlow and published by . This book was released on 1983 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Phase Transfer Catalysis written by Eckehard Volker Dehmlow and published by Wiley-VCH. This book was released on 1993-05-13 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: E. V. Dehmlow, S. S. Dehmlow Phase Transfer Catalysis Third, Revised and Enlarged Edition Phase Transfer Catalysis has matured, and so has this book. Certain PTC-variants have become standard techniques in the lab, and PTC may be on the brink of large-scale use. The new edition describes important new developments in PTC. Furthermore, it has been extensively updated and offers a comprehensive list of very recent references. New material has been added on solid/liquid PTC enantioselective reactions metal-organic reactions reduction and oxidation reactions elimination and substitution reactions
