Download or read book Synthesis of High Molecular Weight Poly methyl Methacrylate by ARGET ATRP written by Jialin Qiu and published by . This book was released on 2015 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesis of poly (methyl methacrylate) by activators regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) was extensively studied. It was observed that when the target molecular weight is higher, side reactions and terminations becomes more prominent. In this study, a facile method was used to synthesize high molecular weight PMMA by ARGET ATRP.The effect of solvent, catalyst and ligand were discussed systematically. Low molecular weight polyethylene glycol (PEG) (600 g/mol) as solvent significantly increased the reaction rate and provides molecular weight as high as 96 kDa within 2h reaction, Ð as low as 1.2. PEG can stabilize the catalyst by complexing to avoid the side reactions such as the reactions between catalyst and chain end. The terminal hydroxyl group could potentially increase the reaction rate. It was also observed that the results have PEG molecular weight dependence. As PEG molecular weight increased, viscosity increased which resulted in poor polymer chain diffusion. However PEG-metal stability constant increased when PEG molecular weight increased which provided better control. These factors competitively affected the polymerization kinetics. Optimum solvent was observed using PEG (600 Da). The comparison between two copper based catalysts CuBr2 and CuCl2 showed that shorter bond length of Cu-Br leaded to a faster reaction rate. For the comparison of ligands, N,N,N',N',N''-pentamethyldiethylenetriamine (PMDETA) as a tridentate ligand had weaker reducing ability but stronger coordination ability compared to tetramethylethylenediamine (TMEDA) as bidentate ligand.Synthesized PMMA was used as macroinitiator to synthesize poly (methyl methacrylate)-block-polystyrene (PMMA-PS) block copolymer by bulk ARGET ATRP. With the increasing amount of styrene, PMMA diffusion became better and prematurely termination was reduced. PMMA-PS with molecular weight of 770 kDa and Ð of 1.32 was successfully synthesized.
Download or read book Encyclopedia of Polymeric Nanomaterials written by Shiro Kobayashi and published by Springer. This book was released on 2015-06-12 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last few years, nanoscience and nanotechnology have been the focus of significant research attention, both from academia and industry. This sustained focus has in-turn driven the interdisciplinary field of material science research to the forefront of scientific inquiry through the creation and study of nanomaterials. Nanomaterials play an important role in the development of new materials as they can be used to influence and control physical properties and specific characteristics of other materials. Nanostructured materials that have been created include nanoparticles, nanocapsules, nanoporous materials, polymer multi-layers to name a few. These are increasingly used across applications as diverse as automotive, environment, energy, catalysis, biomedical, pharmaceutical, and polymer industries. The Encyclopedia of Polymeric Nanomaterials (EPN) intends to be a comprehensive reference work on this dynamic field studying nanomaterials within the context of the relationship between molecular structure and the properties of polymeric materials. Alphabetically organized as an encyclopedic Major Reference Work, EPN will cover the subject along multiple classification axes represented by name, source, properties, function, and structures or even processes, applications and usage. The underlying themes of the encyclopedia has been carefully identified to be based not just on material-based and function-based representation but also on structure- and process-based representation. The encyclopedia will have an exclusive focus on polymeric nanomaterials (for e.g., nanoceramics, nanocomposites, quantum dots, thin films) and will be a first of its kind work to have such an organization providing an overview to the concepts, practices and applications in the field. The encyclopedia intends to cover research and development work ranging from the fundamental mechanisms used for the fabrication of polymeric nanomaterials to their advanced application across multiple industries.
Download or read book Controlled living Radical Polymerization written by Krzysztof Matyjaszewski and published by . This book was released on 2000 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines recent progress in controlled/living radical polymerization. The volume focuses on three synthetic methods: atom transfer radical polymerization, nitroxide mediated polymerization and degenerative transfer via addition fragmentation. In addition, the volume covers the preparation and characterization of many never before seen materials using ATRP, NMP and RAFT.
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 Anionic Synthesis of Narrow Molecular Weight Distribution Poly methyl Methacrylate Poly n butyl Acrylate and Poly methyl Methacrylate poly n butyl Acrylate Block Copolymers at Elevated Temperatures written by Angela P. Zagala and published by . This book was released on 1995 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals of Polymerization written by Broja Mohan Mandal and published by World Scientific. This book was released on 2013 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last twenty years, the field of the chemistry of polymerization witnessed enormous growth through the development of new concepts, catalysts, processes etc. Examples are: non classical living polymerizations (group transfer polymerization, living carbocationic polymerization, living radical polymerization and living ring-opening metathesis polymerization (ROMP)); new catalysts (metallocenes and late transition metal catalysts for stereospecific polymerization, Schrock and Grubbs catalyst for ROMP among others) and new processes such as miniemulsion, microemulsion polymerization and dispersion polymerization (in polar solvents). Apart from the developments in the chemistry of polymerization, methods have been developed for the evaluation of highly reliable rate constants of propagation in radical as well as cationic polymerization. All these have revolutionized the field of synthetic polymer chemistry. In the book, fundamentals of both the new and old polymerization chemistry have been dealt with. The new chemistry has been given nearly equal space along with the old.
Download or read book Advances in Microporous and Mesoporous Materials written by Rafael Huirache Acuña and published by BoD – Books on Demand. This book was released on 2020-07-15 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays, microporous and mesoporous materials are versatile solids of great interest due to their structures and pore sizes, which allow their application in many areas. Accordingly, with IUPAC, materials with pore sizes smaller than 2 nm are called microporous and with pore sizes between 2 and 50 nm are called mesoporous. The pore size has an important impact on the material properties and affects their applications. In addition, high surface area, and their ability to incorporate functional groups on the framework are of great relevance for commercial and science applications. This book intends to provide readers with a comprehensive overview of recent improvements in the microporous and mesoporous materials field.
Download or read book Advances in Controlled living Radical Polymerization written by Krzysztof Matyjaszewski and published by . This book was released on 2003 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Controlled/Living Radical Polymerization presents new developments in controlled/living radical polymerization in three areas: atom transfer radical polymerization (ATRP), nitroxide mediated polymerization (NMP), and reversible addition-fragmentation transfer (RAFT). This book also includes synthesis and characterization of many new materials.
Download or read book ATRP of Bio based Methacrylates for Applications in Super Varnishes written by Masa Alrefai and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "This thesis presents controlled radical polymerization via atom transfer radical polymerization (ATRP) of bio-based monomers to make well-defined polymerswith narrow molecular weight distribution for application in varnish formulations. Initially, traditional ATRP was used to synthesize homopolymers of isobornyl methacrylate (IBOMA) and a methacrylic ester with an average aliphatic side chain consisting of 13 carbon bonds (C13MA). Statistical copolymers of poly(IBOMA-stat-C13MA) with varying IBOMA:C13MA ratios were synthesized, kinetics and molecular characteristics were evaluated and reactivity ratios were determined to predict copolymer compositions from an initial monomer composition. The reactions were conducted at 80C with the bromine-based initiator 4-(2-isobutyrate ethyl morpholine bromide) (ME-Br). Based on the gravimetric conversion analysis and gel permeation chromatography (GPC), the IBOMA and C13MA-rich compositions were all polymerized in a controlled manner (defined as a linear increase in number average molecular weight Mn with conversion up to 99% and low dispersity (Đ=1.16-1.52)). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) studies were performed to evaluate thermal transitions and thermal stability of the copolymers. The glass transition temperatures were found to be 118C and -45C for poly(IBOMA) and poly(C13MA), respectively. Post-polymerization treatments and purification were performed on the resulting polymers in order to remove the metal catalyst residue.A reduced catalyst ATRP method, activator regenerated by electron transfer (ARGET ATRP), is an environmentally friendly ATRP method that can efficiently produce tailor-made polymer structures with only ppm amounts of copper, thereby eliminating post-polymerization purification. ARGET ATRP was explored initially for the synthesis of IBOMA homopolymers. Different reaction parameters, including temperature, type of initiator and solvent, and concentration of solvent, catalyst, ligand, and reducing agent were all investigated. The reaction parameters were optimized to obtain a well-controlled polymerization with a linear increase in number average molecular weight Mn with conversion up to 97% and a relatively low dispersity (Đ=1.5-1.7). The optimized reaction conditions were then utilized to synthesize homopolymers of C13MA and statistical copolymers (poly(IBOMA-stat-C13MA)) with different IBOMA:C13MA ratios. The reactions were well controlled with conversion up to 99% and low dispersity (Đ=1.5). These results suggest the successful incorporation of sustainably sourced monomers into copolymers with a broad range of tunable glass transition temperatures via ARGET ATRP. Further, polymers were prepared to include the epoxy-functional monomer glycidyl methacrylate (GMA) to enhance adhesion properties for the varnish. Therefore, IBOMA/C13MA/GMA terpolymers were synthesized in a well-controlled manner with conversion up to 79% and low dispersity (Đ=1.5). The resulting resins were used to prepare varnish formulations that were tested for minimal drying time and impact resistance"--
Download or read book Controlling the Morphology of Polymers written by Geoffrey R. Mitchell and published by Springer. This book was released on 2016-09-06 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on controlling morphology of different scales for polymers. The authors explain the need for successful control of morphology to yield target macroscopic physical properties in the application of polymers to diverse areas such as engineering materials, nanodielectrics and photonic crystals. The book combines specialized chapters with an introduction to the morphology of polymers and the range of experimental techniques available to evaluate it.
Download or read book Handbook of RAFT Polymerization written by Christopher Barner-Kowollik and published by John Wiley & Sons. This book was released on 2008-09-08 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spanning the entire field from fundamentals to applications in material science, this one-stop source is the first comprehensive reference for polymer, physical and surface chemists, materials scientists, chemical engineers, and those chemists working in industry. From the contents: * Introduction: Living Free Radical Polymerization and the RAFT Process * Fundamental Structure-Reactivity Correlations Governing the RAFT Process * Mechanism and Kinetics * The RAFT Process as a Kinetic Tool * Theory and Practice in Technical Applications * RAFT Polymerization in Bulk and Organic Solvents, as well as Homogeneous Aqueous Systems * Emulsion and Mini-Emulsion Polymerization * Complex Architecture Design * Macromolecular Design via the Interchange of Xanthates * Surface Modification * Stability and Physical Properties of RAFT Polymers * Novel Materials: From Drug Delivery to Opto-Electronics * Outlook and Future Developments
Download or read book Miktoarm Star Polymers written by Ashok Kakkar and published by Royal Society of Chemistry. This book was released on 2017-04-13 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: The term ‘miktoarm polymers’ refers to asymmetric branched macromolecules, a relatively new entry to the macromolecular field. Recent advances in their synthesis and intriguing supramolecular chemistry in a desired medium has seen a fast expansion of their applications. The composition of miktoarm polymers can be tailored and even pre-defined to allow a desired combination of functions, meaning polymer chemists can have complete control of the overall architecture of these macromolecules. By carefully selecting the composition, they can create supramolecular structures with intriguing properties, particularly for applications in biology. Miktoarm Star Polymers features chapters from experts actively working in this field, and provides the reader with a unique introduction to the fundamental principles of this exciting macromolecular system. Topics covered include the design, synthesis, characterization, self-assembly and applications of miktoarm polymers. The book is an excellent overview and up to date guide to those working in research in polymer chemistry, materials science, and polymers for medical applications.
Download or read book Polymer Functionalized Graphene written by Arun Kumar Nandi and published by Royal Society of Chemistry. This book was released on 2021-06-18 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is an immense variety of research on polymer functionalized graphene (PFG). Functionalization of graphene is necessary for improvement of the compatibility with polymers. Applications of these graphene polymer hybrids include in chemical and biological sensing, photovoltaic devices, supercapacitors and batteries, dielectric materials and drug/gene delivery vehicles. This book will shed light on the synthesis, properties and applications of these new materials, covering two methods (covalent and noncovalent) for producing polymer functionalized graphene. Chapters cover physical, optical, mechanical and electronic properties, applications of polymer functionalized graphene in energy harvesting and storage, and uses in biomedicine and bioengineering. Written by an expert in the field, Polymer Functionalized Graphene will be of interest to graduate students and researchers in polymer chemistry and nanoscience.
Download or read book Controlled Living Radical Polymerization written by Krzysztof Matyjaszewski and published by OUP USA. This book was released on 2007-01-04 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The preparation and characterization of new materials with precisely controlled macromolecular dimensions, functionalities, and decomposition, as well as with well-defined topologies, is perhaps the main focus of contemporary polymer synthesis. The best control of molecular functions can be achieved in a controlled/living polymerization -- a chain growth process without chain breaking reactions. Recently, controlled/living polymerizations have extended to radical systems which are not only commercially important, but also have the largest potential due to the availability of radically polymerizable monomers, facile copolymerization and undemanding experimental conditions. Controlled Radical Polymerization will examine recent advances in mechanistic and synthetic aspects of controlled/living radical (co)polymerization systems. Not only will this book be focused on recent progress in the dynamically developing field of controlled/living radical polymerization, but it will be a sequel to the very popular ACS Symposium Series 685, 768, and 854. The book will consist of >30 chapters separated into seven subsections: Fundamentals, Mechanism of ATRP, Mechanisms of SFRP and Degenerative Transfer Processes, Controlled Architecture by CRP, Organic-inorganic Hybrids by CRP, Biomaterials by CRP and Industrial Applications. This book targets chemists and polymer scientists in academia and in industry.
Download or read book Utilization of Atom Transfer Radical Polymerization for Synthesis of Graft Copolymer of Natural Rubber and Poly methylmethacrylate written by Lapporn Vayachuta and published by . This book was released on 2009 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atom Transfer Radical Polymerization (ATRP) technique was applied for synthesis of natural rubber-grafted-poly(methyl methacrylate) (NR-g-PMMA). Active sites on macromolecular chains of NR were created by fixation of bromoalkyl groups via a two-step chemical modification: partial epoxidation on unsaturated carbon-carbon bonds, followed by nucleophilic addition of a bromoalkyl-functionalized carboxylic acid on the oxirane rings of the epoxidized natural rubber (ENR) obtained. The resulting bromoalkyl-functionalized rubber was then used as macroinitiator to initiate the ATRP of methyl methacrylate (MMA) from NR chains by varying reaction conditions. The study was successively envisaged with 4-methyloct-4-ene (a model molecule of NR repeating unit), a synthetic cis-1,4-polyisoprene, and natural rubber. In the first part, the feasibility of the grafting reaction is verified by studying the ATRP of MMA from model molecules of bromoalkyl-functionalized 1,4-polyisoprene units. The model of the 1,4-polysisoprene unit, 4-methyloct-4-ene, is transformed in various models of bromoalkyl-functionalized 1,4-polyisoprene units via a chemical modification procedure carried out in two-steps: epoxidation performed with m-chloroperbenzoic acid (CPBA) followed by the addition of the bromoalkyl-functionalized carboxylic acid (2-bromopropionic acid, A1, or 2-bromo-2-methylpropionic acid, A2) on the oxirane ring formed. The addition of the acid occurs according to an SN2 mechanism with fixation of the acid group on the less substituted carbon of the oxirane ring and is competed with a secondary reaction of rearrangement of oxirane ring, leading to the formation of two allyl alcohols. The yield of the addition depends on the acidity of the carboxylic acid used. Afterwards, resulting O-(2-hydroxy-2-methyl-1-(n-propyl)pentyl)-2-bromopropionate and O-(2-hydroxy-2-methyl-1-(n-propyl)pentyl)-2-bromoisobutyrate, were used to initiate the ATRP of MMA at 90°C in toluene using Cu(I)Br complexed with a polyamine ligand. Several ligands were tested: N-(n-octyl)-2-pyridylmethanimine (NOPMI), N-(n-octadecyl)-2-pyridylmethanimine (NODPMI), and 1,1,4,7,7-pentamethyldiethylenetriamine (PMDETA). A good control of molecular weights (SECn,M) and polydispersity indexes (PDI) were obtained with O-(2-hydroxy-2-methyl-1-(n-propyl)pentyl)-2-bromoisobutyrate as the initiator in presence of CuBr/NOPMI as catalytic system. In the second part, the synthetic cis-1,4-polyisoprene (PI) is transformed into a bromoalkyl-functionalized polyisoprene (PI-Br) macroinitiator using a two-step chemical modification procedure similar to that used for synthesis of the model. PI was partially epoxidized using CPBA in dichloromethane, and then the epoxidized PI (EPI) obtained was reacted with A2. The addition of the acid occurs according to an SN2 mechanism with fixation of the acid group on the less substituted carbon of the oxirane ring ([beta]-addition) and is competed with rearrangement reactions of oxirane rings, leading to external allyl alcohol. SECn,M and PDI of PMMA grafts were determined by Size Exclusion Chromatography after separation from the PI backbone by hydrolysis of the ester bond using trifluoroacetic acid. An internal first order kinetic plot with respect to monomer and an increase of SECn,M with MMA conversion were observed using Cu(I)Br complexed with bidentate (NOPMI and NODPMI) and tridentate (PMDETA) ligands, as catalytic systems. With bidentate ligands, the PDI of grafts is better controlled. Moreover, the control of SECn,M and PDI of PMMA grafts was affected by increasing the degree of initiating units in PI-Br. In the last part, NR is used as a starting material. It was partially epoxidized in ENR in latex medium by reaction with performic acid generated in-situ from formic acid and hydrogen peroxide, and then ENR was transformed in bromoalkyl-functionalized NR (NR-Br) by nucleophilic addition of A2 on the oxirane rings. The addition of the acid is similar to that observed during the studies performed with 4-methyloct-4-ene and PI. Resulting NR-Br was then used to initiate the graft polymerization of MMA from NR chains using normal ATRP in toluene solution and in aqueous dispersed medium, respectively. AGET-ATRP was also considered in aqueous dispersed medium to study the effect of water for further ATRP graft copolymerization studies with NR latices. By normal ATRP in toluene solution, the termination reactions by recombination decreased as MMA concentration deceased, from 30 wt% to 10 wt%. PDIs of PMMA grafts vary in range from 1.7 (at 8.1 % MMA conversion) to 2.0 (at 52.0 % MMA conversion). A better control of the SECn,M and PDI of PMMA grafts was obtained by using normal ATRP in aqueous dispersed medium, more especially when CuBr was complexed with NODPMI. In these conditions, PDIs of PMMA grafts were low (closed to 1.5 at low MMA conversion). In AGET-ATRP performed in aqueous dispersed medium, it was shown that the efficiency of graft copolymerization is affected by the concentration in ascorbic acid used as reducing agent. The chemical structures obtained were characterized by FT-IR, and by 1H and 13C NMR. The thermal properties of the graft copolymers synthesized were studied by Differential Scanning Calorimetry (DSC). The presence of two Tgs, at about -14°C and 99°C respectively, on the DSC curves when the amounts of PMMA in NR-g-PMMAs are higher than 65 wt%, shows that these materials adopt a biphasic morphology.
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 Copper Catalysis in Organic Synthesis written by Gopinathan Anilkumar and published by John Wiley & Sons. This book was released on 2020-07-08 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most current information on growing field of copper catalysis Copper Catalysis in Organic Synthesis contains an up-to-date overview of the most important reactions in the presence of copper catalysts. The contributors—noted experts on the topic—provide an introduction to the field of copper catalysis, reviewing its development, scope, and limitations, as well as providing descriptions of various homo- and cross-coupling reactions. In addition, information is presented on copper-catalyzed C–H activation, amination, carbonylation, trifluoromethylation, cyanation, and click reactions. Comprehensive in scope, the book also describes microwave-assisted and multi-component transformations as well as copper-catalyzed reactions in green solvents and continuous flow reactors. The authors highlight the application of copper catalysis in asymmetric synthesis and total synthesis of natural products and heterocycles as well as nanocatalysis. This important book: Examines copper and its use in organic synthesis as a more cost-effective and sustainable for researchers in academia and industry Offers the first up-to-date book to explore copper as a first line catalyst for many organic reactions Presents the most significant developments in the area, including cross-coupling reactions, C–H activation, asymmetric synthesis, and total synthesis of natural products and heterocycles Contains over 20 contributions from leaders in the field Written for catalytic chemists, organic chemists, natural products chemists, pharmaceutical chemists, and chemists in industry, Copper Catalysis in Organic Synthesis offers a book on the growing field of copper catalysis, covering cross-coupling reactions, C–H activation, and applications in the total synthesis of natural products.
