Download or read book Copolymer Synthesis and Characterization by Post Polymerization Modification written by Casey James Galvin and published by . This book was released on 2014 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Ionically Bonded Diblock Copolymers written by Lei Feng (Chemical engineer) and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers consist of two or more incompatible polymer chains linked by covalent bonds. These block copolymer can separate into nanometer sized domains whose morphology depends upon the size of the block and interactions between them. The properties of block copolymers can be modified and potentially improved by introducing noncovalent interactions to replace covalent linkages between blocks to form supramolecular block copolymers. These kinds of materials combine the microphase separation inherent to block copolymers with the facile synthesis of supramolecular materials thereby affording new and unique materials. This dissertation focuses on synthesis and characterization of PS-b-PMA block copolymers with ion-pair junctions.Firstly, the chain-end sulfonated polystyrene ([omega]-sulfonated PS) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization and postpolymerization modification. In the postpolymerization modification two methods were investigated: in the first one, the polymer was converted to a thiol-terminated polymer by aminolysis. Then a sulfonic acid end-group was produced then by oxidation of the thiol end-group with m-chloroperoxybenzoicacid (m-CPBA); in the second method, the RAFT-polymerized polymer was directly sulfonated by oxidation with m-CPBA. After purification by column chromatography, [omega]-sulfonated PS was obtained by both methods with greater than 95% end-group functionality as measured by titration. The sulfonic acid end-group could be neutralized with various ammonium or imidazolium counter ions through acid-base or ionic metathesis reactions. These polymers with ionic end-group can be used as model supramolecular building blocks.Secondly, ammonium end functionalized polymethylacrylate (PMA) was synthesized directly by RAFT polymerization using functional RAFT agent. Then chain-end sulfonated polystyrene and ammonium end functionalized polymethylacrylate (PMA) were used to synthesize A-B block copolymers by two different methods: the first method was by mixing two oppositely charged end group functionalized polymers; the second method was to ionically bond a RAFT agent to the chain end of an end sulfonated polymer to generate a supramolecular macro RAFT agent then an A-B block copolymer was prepared by RAFT polymerization using supramolecular macro-RAFT agent. The polymerization kinetics were investigated and the molecular weight and the chemical structure of the block copolymers were characterized by 1H-NMR and SEC. The results show that the ion-bonded supramolecular block copolymer, PS-PMA, have been successfully prepared with controlled molecular weight and narrow distribution.Thirdly, the morphology of the ion-bonded supramolecular PS-PMA diblock copolymers were investigated by small-angle X-ray scattering (SAXS) and rheological techniques. Several covalently bonded PS-PMA block copolymers were synthesized by RAFT polymerization and their micro domain structures and rheology behaviors were also investigated. The results showed that the electrostatic interactions between the end ion groups are able to overcome the thermodynamic repulsion of two blocks result in the formation of diblock copolymers with similar behaviors and morphology of traditional covalent bonded diblock copolymers and their micro domain structures remain to high temperatures.
Download or read book Block Copolymers in Nanoscience written by Massimo Lazzari and published by Wiley-VCH. This book was released on 2007-06-27 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first book to take a detailed look at one of the key focal points where nanotechnology and polymers meet provides both an introductory view for beginners as well as in-depth knowledge for specialists in the various research areas involved. It investigates all types of application for block copolymers: as tools for fabricating other nanomaterials, as structural components in hybrid materials and nanocomposites, and as functional materials. The multidisciplinary approach covers all stages from chemical synthesis and characterization, presenting applications from physics and chemistry to biology and medicine, such as micro- and nanolithography, membranes, optical labeling, drug delivery, as well as sensory and analytical uses.
Download or read book Plasma Modification of Polyolefins written by N. S. Baneesh and published by Springer Nature. This book was released on 2021-11-22 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses plasma modification of polyolefin surfaces. It comprises 21 chapters divided into three major sections. The first section covers the different techniques used for plasma modification of polyolefin surfaces and the effects of various gases as a surrounding medium, while the second provides a detailed analysis of the physics and chemistry of plasma modification and discusses various innovative characterization techniques, as well as ageing of the modified surface. It focuses on the analysis of changes in polymers’ surface chemistry using various spectroscopic techniques, and of changes in their surface morphology after plasma treatment using optical microscopy, electron microscopy and atomic force microscopy. In addition, it provides detailed information on the characterization of modified polymer surfaces. The book’s third and last section covers a range of applications of plasma-modified polyolefin surfaces varying from the packaging industry to the biomedical field, and shares valuable insights on the lifecycle analysis of plasma modification and modified surfaces.
Download or read book Synthesis and Characterization of Block Copolymer Anion Exchange Membranes and Superimide Proton Exchange Membranes written by Lizhu Wang and published by . This book was released on 2014 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Novel Biodegradable Copolymers written by Christopher Paul Radano and published by . This book was released on 2003 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Dye labeled Copolymers by Reversible Addition fragmentation Transfer RAFT Polymerization written by Binxin Li and published by . This book was released on 2008 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Copolymers of N-(2-hydroxypropyl)methacrylamide (HPMA) and N-hydroxysuccinimide methacrylate (NMS) were synthesized by reversible addition-fragmentation transfer (RAFT) polymerization using a semi-batch method. The copolymers were prepared in a wide range of molecular weights (Mn = 4,200-14,000 g/mol) with narrow polydispersities (1.2-1.4). A new approach was developed to prepare a modified RAFT chain transfer agent, a naphthalimide-dye-labeled dithiobenzoate. It was used to prepare a naphthalimide-dye end-labeled poly(HPMA-co-NMS). The copolymer was characterized by four different methods, 1H NMR spectroscopy via end group characterization and using 3-(trimethylsilyl)propionic acid-d 4 sodium salt (TSP) external standard, end group analysis by UV-Vis spectroscopy and by GPC. The results obtained from these measurements are in good agreement.
Download or read book Synthesis and Characterization of Modified Poly arylene Ether Ether Ketone Copolymers written by Shilain Denny Wu and published by . This book was released on 1987 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Modified Block Copolymers written by Chi-Fung Chu and published by . This book was released on 1988 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Applications of Copolymers written by Anbanandam Parthiban and published by John Wiley & Sons. This book was released on 2014-06-23 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the reactivity of monomers is crucial in creating copolymers and determining the outcome of copolymerization. Covering the fundamental aspects of polymerization, Synthesis and Applications of Copolymers explores the reactivity of monomers and reaction conditions that ensure that the newly formed polymeric materials exhibit desired properties. Referencing a wide-range of disciplines, the book provides researchers, students, and scientists with the preparation of a diverse variety of copolymers and their recent developments, with a particular focus on copolymerization, crystallization, and techniques like nanoimprinting and micropatterning.
Download or read book Synthesis and Characterization of Polymers Incorporating N alkyl Urea peptoid Sequences written by Xiaoping Chen and published by . This book was released on 2013 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation is mainly based on the works of synthesis and characterization of polymer/N-alkyl urea peptoid hybrid materials. Polymers were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization using thrithiocarbonate and dithiocarbonate chain transfer agents in controlled manner. Poly(N-alkyl urea peptoid) was synthesized via step growth polymerization using symmetric diamine and diisocyanate. N-Alkyl urea peptoid sequences up to sixmer were synthesized through three steps repetition cycles in good yields. Several different hybrid polymeric materials were explored combining the three different material synthetic strategies including polymer conjugates shown in chapter 2, molecular brushes shown in chapter 3, water soluble A-B-A triblock copolymer shown in chapter 4. Firstly, two well-defined statistical copolymers poly(styrene-co-3-azidopropyl methacrylate) and poly(3-O-methacryloyl-1,2:5,6-di-O-isopropylidene-[subscript D]-glucofuranose -co-AzPMA) were synthesized by RAFT. An exemplary N-alkyl urea peptoid trimer was synthesized and conjugated to the two copolymers through the 'click' reaction of the azide pendent group of polymers with the complilanry alkene group at N-alkyl urea peptoid. The polymer conjugates were subjected to further post-modification to generated fluorescent conjugates or water soluble materials. Following the explore of conjugation, N-alkyl urea peptoid was used as comonomer to synthesize linear poly(N-alkyl urea peptoid). The RAFT agent was introduced onto the linear polymer generated by step growth polymerization once again through 'click' reaction. Sequentially, styrene and tert-butyl acrylate was grown from RAFT agents sites that fused onto the poly(N-alkyl urea peptoid) backbone to make block copolymer arms. Upon removal of the tert-butyl groups, the molecular brushes were observed to generate micelles in aqueous solution. The self-assembly N-alkyl urea peptoid was then investigated and conjugated to water soluble polymer poly(ethylene glycol) to produce a A-B-A block copolymer that self-assembled into ribbons in aqueous solution. The final two part of dissertation was about gelling materials studies starting with presenting a synthesis strategy for low molecular weight organogelators (LMOG) using the ureidopyrimidinone (UPy) group functioned N-alkyl urea peptoid. The surprising observation of gelation in DMSO led to extensive investigation of the gelification mechanism studies. Based on the lessons of LMOG, the copolymerization of different T[subscript g] monomers with quadruple hydrogen bonding containing methacrylate was demonstrated suitable to produce polymeric organogelators in the final chapter.
Download or read book Synthesis Characterization and Applications of Functionalized Polyglycolides written by Erin B. Vogel and published by . This book was released on 2008 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Copolymers Based on 2 3 4 5 6 pentafluorostyrene written by Marta Paz Pazos and published by . This book was released on 2005 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: 2,3,4,5,6-Pentafluorostyrene (PFS) was polymerized in the presence of a solution of polybutadiene (PB) in tetrahydrofuran using benzoyl peroxide as the radical initiator at 50, 60, 80 °C. The products were graft copolymers of poly(2,3,4,5,6-pentafluorostyrene) (PPFS) into PB. The copolymerizations follow typical free radical polymerization kinetics and behavior, with the rate of propagation proportional to the monomer concentration and the square root of the initiator concentration. Gel permeation chromatography (GPC) equipped with two detectors (UV and refractive index) has allowed us to determine conversion of the monomer, graft efficiency, graft ratio and graft frequency of the grafted products obtained at different temperatures and initiator concentrations, without the need of purification and/or isolation of the final graft copolymer. Conversion of the monomer and graft ratio increase and grafting frequency decreases with increasing temperature and initiator concentration. The grafting efficiencies and grafting ratios are consistent with a system that terminates mainly by combination and whose graft sites are generated by hydrogen abstraction of allylic radicals by initiator primary radicals. Pure graft copolymers were isolated by extracting unreacted PB into hexanes and PPFS homopolymer generated as a side-product into acetone. The similarity of the glass transition temperatures of the PPFS grafts and the corresponding extracted PPFS homopolymers confirms that their lengths are approximately equal. We also attempted to react PFS with PB by an ene reaction, which would result in PB modified with perfluorinated rings connected to the PB backbone through a two carbon spacer. However, we were not able to perform the modification either with PB or with model compounds. One of the reactions tested was PFS with [beta]-pinene, which resulted in the copolymerization of them. The copolymer products are composed of isolated units of [beta]-pinene randomly distributed between blocks of PFS segments, as evidenced from their copolymer reactivity ratios and their glass transitions. PFS was also copolymerized in bulk with styrene (at 70 and 25 °C), 1-vinyl naphthalene (at 70 and 25 °C) and 2-vinyl naphthalene (at 70 °C). In all the systems investigated the copolymer reactivity ratios are indicative of copolymerization with strong tendency to alternation. NMR spectroscopy shows evidence for this alternation by both new resonances and shifting of resonances present in the homopolymers. In addition, their thermal behavior is consistent with that of alternating copolymers. They exhibit only one glass transition, at a temperature greater than the weighted average of the glass transitions of the two homopolymers. The alternation tendency and thermal behavior of the copolymers are attributed to strong interactions developed between perfluorinated aromatic rings and regular aromatic hydrocarbons.
Download or read book Functional Polymers by Post Polymerization Modification written by Patrick Theato and published by John Wiley & Sons. This book was released on 2013-02-12 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: In modern polymer science a variety of polymerization methods for the direct synthesis of polymers bearing functional groups are known. However, there is still a large number of functional groups that may either completely prevent polymerization or lead to side reactions. Post-polymerization modification, also known as polymer-analogous modification, is an alternative approach to overcome these limitations. It is based on the polymerization of monomers with functional groups that are inert towards the polymerization conditions but allow a quantitative conversion in a subsequent reaction step yielding a broad range of other functional groups. Thus, diverse libraries of functional polymers with identical average degrees of polymerization but variable side chain functionality may easily be generated. Filling the gap for a book dealing with synthetic strategies and recent developments, this volume provides a comprehensive and up-to-date overview of the field of post-polymerization modification. As such, the international team of expert authors covers a wide range of topics, including new synthetic techniques utilizing different reactive groups for post-polymerization modifications with examples ranging from modification of biomimetic and biological polymers to modification of surfaces. With its guidelines this is an indispensable and interdisciplinary reference for scientists working in both academic and industrial polymer research.
Download or read book Chemistry of Polymeric Metal Chelates written by Gulzhian I. Dzhardimalieva and published by Springer. This book was released on 2018-02-13 with total page 1036 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the chemistry of polymeric metal chelates. The main results and the production and chemical structure of polymers with chelate units as well as the specificity of metal complex binding of different structure are presented here. This book also reveals the transformations which components undergo in the course of chelation. Special attention is paid not only to synthetic but also to natural (including living) systems. The usage of polymeric metal chelates and their development are examined. The related research was performed for chelates with chain structure. This book is useful to researchers being active in synthesis and design of macromolecular metal chelates
Download or read book Synthesis and Characterization of Photocleavable Polymers and Block Copolymers written by Hui Zhao and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Temperature and Light responsive Polymers and Block Copolymers written by Florian D. Jochum and published by . This book was released on 2010 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt:
