Download or read book Synthesis and Characterization of Star Shaped Block Copolymers Via Cationic Ring Opening and Photoinitiated Radical Polymerizations written by Dolunay Şakar and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Various Macromolecular Architectures by Using Combined Controlled and Photoinitiated Polymerization Methods written by Ali Ekrem Müftüoğlu and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced polymeric materials with specialized properties are of great interest. Block and graft copolymers are the most demanded advanced materials since they display combined physical and mechanical properties. Because of their diverse macromolecular structures, they may possess novel characteristics required for many high-tech applications. Therefore, engineering macromolecular architectures is one of the major goals in polymer chemistry. Controlled polymerization methods appear to be the most powerful and versatile tools in achieving this goal. in the present work, macromolecular chains of various chemical compositions were ~ assembled in original topologies by combination of Atom Transfer Radical Polymerization (ATRP) or Ring-opening Polymerization (ROP) with photoinduced radical or radical promoted cationic polymerizations. These macromolecular architectures involve block, graft, block-graft, and brush type copolymers as well as miktoarm star copolymers and hyper-branched polymers... For this purpose, end-chain, mid-chain or side-chain mono- or bi- amino- or N;N- dimethylamino- functional precursor polymers were prepared either by A TRP or ROP. Subsequently, these prepolymers served as macromolecular co-initiators in photoinduced radical or promoted cationic polymerizations. For the preparation of diblock copolymers, N,N-dimethylaniline end-functional polystyrenes (PSt) with well-defined structures and low polydispersities were synthesized by A TRP of styrene in bulk at 11 O0C using 4-( dimethylamino )benzyl 4- (bromomethyl) benzoate as initiator in conjunction with a cuprous complex, Cu(I)Br/bipyridine. These polym'ers were further used in block copolymerization with methyl methacrylate (MMA) and cyclohexene oxide (CHO) via photoinduced radical and radical promoted cationic polymerization routes, respectively, as represented by (1) and (2). in the former case, macroradical generation was achieved with benzophenone sensitizer by photoexcitation followed by hydrogen abstraction from amino end groups. A visible light initiating system has been utilized in the radical promoted cationic polymerization of CHO. The system involves a xanthene dye (Erythrosin B) as the sensitizer, an aromatic N;N-dimethylamino group and diphenyl iodonium hexafluorophosphate as the radical source and radical oxidizer, respectively. While pure block copolymers were obtained in the free radical route, the free radical promoted cationic polymerization yielded both block and homopolymers...
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 Synthesis of Block Copolymers Via Combination of Cationic Ring Opening and Atom Transfer Radical Polymerizations written by Nadin Narsisoğlu and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Developments in Block Copolymer Science and Technology written by Ian W. Hamley and published by John Wiley & Sons. This book was released on 2004-07-16 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focuses on recent advances in research on block copolymers, covering chemistry (synthesis), physics (phase behaviors, rheology, modeling), and applications (melts and solutions). Written by a team of internationally respected scientists from industry and academia, this text compiles and reviews the expanse of research that has taken place over the last five years into one accessible resource. Ian Hamley is the world-leading scientist in the field of block copolymer research Presents the recent advances in the area, covering chemistry, physics and applications. Provides a broad coverage from synthesis to fundamental physics through to applications Examines the potential of block copolymers in nanotechnology as self-assembling soft materials
Download or read book Handbook of Telechelic Polyesters Polycarbonates and Polyethers written by Sophie M. Guillaume and published by CRC Press. This book was released on 2017-03-31 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Telechelic polymers have garnered a great deal of scientific interest due to their reactive chain-end functions. This comprehensive book compiles and details the basic principles of and cutting-edge research in telechelic polyesters, polycarbonates, and polyethers, ranging from synthesis to applications. It discusses general strategies toward telechelic polymers, centered on the fundamental aspects of polycondensation reactions, of cationic, anionic, coordination-insertion, and activated monomer mechanisms of the metal-, enzyme-, or otherwise organocatalyzed ring-opening polymerization of cyclic monomers, and of postpolymerization chemical modification methods of polymer precursors. All main classes of polymers are covered separately, comprising polyhydroxyalkanoates, poly(ε-caprolactone)s, poly(lactic acid)s, polylactides, polycarobnates, and polyethers, including synthetic approaches as well as some illustrative, up-to-date examples and uses. The book also addresses applications of hydroxyl, thiol, amino, or acrylate/methacrylate end-capped polymers as starting materials for the preparation of diverse polymer architectures ranging from block, graft, and star-shaped polymers and micelles to precursors for ATRP macroinitiators, polyurethane copolymers, shape-memory polymers, or nanosized drug delivery systems. The book will appeal to advanced undergraduate- and graduate-level students of polymer science; researchers in macromolecular science, especially those with an interest in functional and reactive polymers; and polymer chemists in academia and industry.
Download or read book Syntheses and Characterization of Multi functional Initiators for Star Block and Cationic Ring opening Polymerizations written by Yusuf Ziya Menceloğlu and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study new multifunctional initiators were synthesized and their polymerization ability were studied. Bi and multifunctional initiators for block and star polymerization have been synthesized by using insertion reaction of tetrakis(dimethyl-amino)-titan (T4) with a,a'-azo-isobutyronitrile (AIBN), T4 with tetracyanoethylene(TCE) and T4 with isophorone diisocyanate (IPDI) respectively, in dry benzene under the nitrogen blanket at 35 oC. New cationic initiators; N-benzyl phthalimide derivatives,N-(a-methylbenzyl) benzothiazoloneandbenzyl benzenesulfonate which have no inorganic salt structure have been synthesized by the reaction of phthalimide, 4-nitro phthalimide, benzothiazolone and benzenesulfonyl chloride with benzyl, alpha and para substituted benzyl halides in the presence of base. All initiators were characterized byphysicochemical, spectral and analytical data. Polymerization ability of these initiators were studied with common monomers such as styrene acrylonitrile (AN)glycidyl phenyl ether (GPE), cyclohexene oxide (CHO), trimethylene oxide (TMO), 2-methyl aziridine (MA) and hydroxyl terminated polybutadiene (Poly bd, R-45 HT). This work suggests that bifunctional initiator 2,2'- azobis isobutyro(tris N"-dimethyl amino titanium-N,N dimethyl)amidin (T4-AZO1) is effective for the synthesis of block copolymer of acrylonitrile with radicalic polymerizable monomers, multifunctional initiators Tetrakis(2 dimethyl amino, N"titanamidin) 2,azoisobutyronitrile (T4-AZO4), Tetra(N'dimethylamino-tris Tetrakis (3,methylene-N dimethyl ureido titanium) 3,5,5 trimethyl cyclohexyl isocyanate or Tetrakis (N'dimethyl N titanium ureido)3,5,5 trimethyl cyclohexyl isocyanate (T4 IPDI4 )are capable for preparing star shape polymers from radicalic polymerizable monomers by decomposition of azo groups incorporated to the related initiators and acrylonitrile by insertion polymerization, furthermore ,model network of hydroxyl terminated polybutadiene was achieved using four-fonctional isocyanate compound T4-IPDI4 via urethane bond formation. Neutral organic compound containing benzylic group bound to low nucleophilic moiety can thermally initiate the cationic polymerization of a 2-methyl aziridine and trimethylene oxide.
Download or read book Controlled living Polymerizations written by Christina Troeltzsch and published by . This book was released on 2003 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Block Copolymers written by Francisco Balta Calleja and published by CRC Press. This book was released on 2000-06-09 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt: A summary of block copolymer chemical structures and synthesis. It discusses physical methods of characterization such as computer simulation, microhardness, dielectric spectroscopy, thermal mechanical relaxation, ultrasonic characterization, transmission electron microscopy, X-ray scattering, and NMR, among others. It also outlines rheological and processing parameters in the multiphase polymer systems with stable microstructures.
Download or read book Block Copolymers I written by Volker Abetz and published by Springer Science & Business Media. This book was released on 2005-12-02 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1 N. Hadjichristidis, M. Pitsikalis, H. Iatrou: Synthesis of Block Copolymers.- 2 V. Abetz: Phase Behaviour and Morphologies of Block Copolymers.-
Download or read book Block Copolymers written by Nikos Hadjichristidis and published by John Wiley & Sons. This book was released on 2003-04-28 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers may be classified as either homopolymers, consisting of one single repeating unit, or copolymers, consisting of two or more distinct repeating units. Block copolymers contain long contiguous blocks of two or more repeating units in the same polymer chain. Covering one of the hottest topics in polymer chemistry, Block Copolymers provides a coherent overview of the synthetic routes, physical properties, and applications of block copolymers. This pioneering text provides not only a guideline for developing synthetic strategies for creating block copolymers with defined characteristics, but also a key to the relationship between the physical properties of block copolymers and the structure and dynamics of materials. Covering features of the chemistry and physics of block copolymers that are not found in comparable texts, Block Copolymers illustrates the structure-activity relationship of block copolymers and offers suggestions for the design of specific applications. Divided into five sections-Block Copolymers includes chapters on: * Block Copolymers by Chemical Modification of Precursor Polymers * Nonlinear Block Copolymers * Adsorption of Block Copolymers at Solid-Liquid Interfaces * Theory of Block Copolymer Segregation * Phase Transformation Kinetics * Block Copolymer Morphology * Block Copolymer Dynamics Polymer chemists, physicists, chemical engineers, and materials scientists, as well as graduate students in polymer science, will find Block Copolymers to be an invaluable text.
Download or read book Les Vrais Incroyables ou les M tamorphoses modernes written by and published by . This book was released on 1798 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ring opening Polymerization written by James E. McGrath and published by . This book was released on 1985 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Silicon Containing Copolymers written by Sahar Amiri and published by Springer. This book was released on 2014-08-22 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicones have unique properties including thermal oxidative stability, low temperature flow, high compressibility, low surface tension, hydrophobicity and electric properties. These special properties have encouraged the exploration of alternative synthetic routes of well defined controlled microstructures of silicone copolymers, the subject of this Springer Brief. The authors explore the synthesis and characterization of notable block copolymers. Recent advances in controlled radical polymerization techniques leading to the facile synthesis of well-defined silicon based thermo reversible block copolymers are described along with atom transfer radical polymerization (ATRP), a technique utilized to develop well-defined functional thermo reversible block copolymers. The brief also focuses on Polyrotaxanes and their great potential as stimulus-responsive materials which produce poly (dimethyl siloxane) (PDMS) based thermo reversible block copolymers.
Download or read book Liquid Crystalline Rod coil Block Copolymers by Stable Free Radical Polymerization written by Padma Gopalan and published by . This book was released on 2002 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Stimuli Responsive Block Copolymers Self assembly Behavior and Applications written by Michael Duane Determan and published by . This book was released on 2006 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water-soluble stimuli responsive block copolymers are a rapidly emerging class of materials with great potential in biomedical and technological applications. In this work a novel class of pentablock copolymers are synthesized via atom transfer radical polymerization techniques and their stimuli-responsive self-assembly properties are characterized. Aqueous solutions of these materials are observed to form micelles and hydrogels in response to changes in both temperature and pH. Cryogenic transmission electron microscopy (cryo-TEM) and small angle neutron and X-ray scattering (SANS and SAXS) techniques are used to investigate the nanoscale structures formed by these pentablock copolymers in solution. The gel structure and mechanical properties are investigated with SANS and rheological techniques. The multi-responsive properties of these materials are utilized to formulate a stimuli responsive drug delivery formulation that exhibits thermoreversible gelation and pH dependent release rate of model drugs.
Download or read book Synthesis and Characterization of Poly methacrylamide styrene Block Copolymer Via Free Radical Polymerization and Reverse Addition fragmentation Chain Transfer raft Polymerization written by Nor Arbani Sean and published by . This book was released on 2015 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
