Radical Chain Polymerization
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Controlled/Living Radical Polymerization in Aqueous Media: Homogeneous and Heterogeneous Systems
Prog. Polym. Sci. 26 =2001) 2083±2134 www.elsevier.com/locate/ppolysci Controlled/living radical polymerization in aqueous media: homogeneous and heterogeneous systems Jian Qiua, Bernadette Charleuxb,*, KrzysztofMatyjaszewski a aDepartment of Chemistry, Center for Macromolecular Engineering, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA bLaboratoire de Chimie MacromoleÂculaire, Unite Mixte associeÂe au CNRS, UMR 7610, Universite Pierre et Marie Curie, Tour 44, 1er eÂtage, 4, Place Jussieu, 75252 Paris cedex 05, France Received 27 July 2001; accepted 30 August 2001 Abstract Controlled/living radical polymerizations carried out in the presence ofwater have been examined. These aqueous systems include both the homogeneous solutions and the various heterogeneous media, namely disper- sion, suspension, emulsion and miniemulsion. Among them, the most common methods allowing control ofthe radical polymerization, such as nitroxide-mediated polymerization, atom transfer radical polymerization and reversible transfer, are presented in detail. q 2001 Elsevier Science Ltd. All rights reserved. Keywords: Aqueous solution; Suspension; Emulsion; Miniemulsion; Nitroxide; Atom transfer radical polymerization; Reversible transfer; Reversible addition-fragmentation transfer Contents 1. Introduction ..................................................................2084 2. General aspects ofconventional radical polymerization in aqueous media .....................2089 2.1. Homogeneous polymerization .................................................2089 -
Cationic/Anionic/Living Polymerizationspolymerizations Objectives
Chemical Engineering 160/260 Polymer Science and Engineering LectureLecture 1919 -- Cationic/Anionic/LivingCationic/Anionic/Living PolymerizationsPolymerizations Objectives • To compare and contrast cationic and anionic mechanisms for polymerization, with reference to free radical polymerization as the most common route to high polymer. • To emphasize the importance of stabilization of the charged reactive center on the growing chain. • To develop expressions for the average degree of polymerization and molecular weight distribution for anionic polymerization. • To introduce the concept of a “living” polymerization. • To emphasize the utility of anionic and living polymerizations in the synthesis of block copolymers. Effect of Substituents on Chain Mechanism Monomer Radical Anionic Cationic Hetero. Ethylene + - + + Propylene - - - + 1-Butene - - - + Isobutene - - + - 1,3-Butadiene + + - + Isoprene + + - + Styrene + + + + Vinyl chloride + - - + Acrylonitrile + + - + Methacrylate + + - + esters • Almost all substituents allow resonance delocalization. • Electron-withdrawing substituents lead to anionic mechanism. • Electron-donating substituents lead to cationic mechanism. Overview of Ionic Polymerization: Selectivity • Ionic polymerizations are more selective than radical processes due to strict requirements for stabilization of ionic propagating species. Cationic: limited to monomers with electron- donating groups R1 | RO- _ CH =CH- CH =C 2 2 | R2 Anionic: limited to monomers with electron- withdrawing groups O O || || _ -C≡N -C-OR -C- Overview of Ionic Chain Polymerization: Counterions • A counterion is present in both anionic and cationic polymerizations, yielding ion pairs, not free ions. Cationic:~~~C+(X-) Anionic: ~~~C-(M+) • There will be similar effects of counterion and solvent on the rate, stereochemistry, and copolymerization for both cationic and anionic polymerization. • Formation of relatively stable ions is necessary in order to have reasonable lifetimes for propagation. -
The Chemistry of Radical Polymerization
THE CHEMISTRY OF RADICAL POLYMERIZATION THE CHEMISTRY OF RADICAL POLYMERIZATION GRAEME MOAD CSIRO Molecular and Health Technologies Bayview Ave, Clayton, Victoria 3168, AUSTRALIA and DAVID H. SOLOMON Department of Chemical and Biomolecular Engineering. University of Melbourne, Victoria 3010, AUSTRALIA Dr Graeme Moad CSIRO Molecular and Health Technologies Bayview Ave, Clayton, Victoria 3168 AUSTRALIA Email: [email protected] Prof David H. Solomon Department of Chemical and Biomolecular Engineering. University of Melbourne Victoria 3010 AUSTRALIA Email: [email protected] Contents Contents............................................................................................................................ v Index to Tables.............................................................................................................xvi Index to Figures ............................................................................................................ xx Preface to the First Edition .....................................................................................xxiii Preface to the Second Edition..................................................................................xxv Acknowledgments......................................................................................................xxvi 1 INTRODUCTION.................................................................................................. 1 1.1 References ........................................................................................................... -
Poly(Sodium Acrylate)-Based Antibacterial Nanocomposite Materials
Poly(Sodium Acrylate)-Based Antibacterial Nanocomposite Materials Samaneh Khanlari Thesis submitted to the Faculty of Graduate and Postdoctoral Studies in partial fulfillment of the requirements for the degree of Doctorate in Philosophy in Chemical Engineering Department of Chemical and Biological Engineering Faculty of Engineering UNIVERSITY OF OTTAWA © Samaneh Khanlari, Ottawa, Canada, 2015 i ii Abstract Polymer-based bioadhesives for sutureless surgery provide a promising alternative to conventional suturing. In this project, a new poly(sodium acrylate)-based nanocomposite with antibacterial properties was developed. Poly(sodium acrylate), was prepared using a redox solution polymerization at room temperature; this polymer served as a basis for a nanocomposite bioadhesive material using silver nanoparticles. In-situ polymerization was chosen as a nanocomposite synthesizing method and three methods were applied to quantify the distribution and loadings of nanofiller in the polymer matrices. These included the Voronoi Diagram, Euclidean Minimum Spanning Tree (EMST) method and pixel counting. Results showed that pixel counting combined with the EMST method would be most appropriate for nanocomposite morphology quantification. Real-time monitoring of the in-situ polymerization of poly(sodium acrylate)- based nanocomposite was investigated using in-line Attenuated Total Reflectance/Fourier Transform infrared (ATR-FTIR) technique. The ATR-FTIR spectroscopy method was shown to be valid in reaction conversion monitoring using a partial least squares (PLS) multivariate calibration method and the results were consistent with the data from off-line water removal gravimetric monitoring technique. Finally, a second, more degradable polymer (i.e., gelatin and poly(vinyl alcohol)) was used to modify the degradation rate and hydrophilicity of the nanocomposite bioadhesive. -
Synthesis and Characterization of Solution and Melt Processible Poly(Acrylonitrile-Co-Methyl Acrylate) Statistical Copolymers
SYNTHESIS AND CHARACTERIZATION OF SOLUTION AND MELT PROCESSIBLE POLY(ACRYLONITRILE-CO-METHYL ACRYLATE) STATISTICAL COPOLYMERS Padmapriya Pisipati Dissertation submitted to the faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Macromolecular Science and Engineering James E. McGrath, Chair Judy S. Riffle, Acting Chair Eugene G. Joseph Sue J. Mecham Donald G. Baird 02/20/2015 Blacksburg, VA Keywords: melt processability, polyacrylonitrile, carbon fibers, methyl acrylate, acrylic fibers, plasticizer, solution processing, high tensile modulus Copyright 2015, Padmapriya Pisipati SYNTHESIS AND CHARACTERIZATION OF SOLUTION AND MELT PROCESSIBLE POLY (ACRYLONITRILE-CO-METHYL ACRYLATE) STATISTICAL COPOLYMERS ABSTRACT Padmapriya Pisipati Polyacrylonitrile (PAN) and its copolymers are used in a wide variety of applications ranging from textiles to purification membranes, packaging material and carbon fiber precursors. High performance polyacrylonitrile copolymer fiber is the most dominant precursor for carbon fibers. Synthesis of very high molecular weight poly(acrylonitrile-co-methyl acrylate) copolymers with weight average molecular weights of at least 1.7 million g/mole were synthesized on a laboratory scale using low temperature, emulsion copolymerization in a closed pressure reactor. Single filaments were spun via hybrid dry-jet gel solution spinning. These very high molecular weight copolymers produced precursor fibers with tensile strengths averaging 954 MPa with an elastic modulus of 15.9 GPa (N = 296). The small filament diameters were approximately 5 µm. Results indicated that the low filament diameter that was achieved with a high draw ratio, combined with the hybrid dry-jet gel spinning process lead to an exponential enhancement of the tensile properties of these fibers. -
Polymer Chemistry
CLOTHWORKERS LIBRARY UNIVERSITY OF LEEDS THERMAL AND OXIDATIVE DEGRADATION OF AN AROMATIC POLYAMIDE. by «. Shojan Nanoobhai Patel 2. Submitted in accordance with the requirement for the degree of Doctor of Philosophy under the supervision of Professor I.E. McIntyre and Dr. S.A. Sills. The candidate confirms that the work submitted is his own and that appropriate credit has been given where reference has been made to work of others. Department of Textile Industries, The University of Leeds, Leeds, LS2 9JT. December 1992. CLASS MARK T:; ~S 2tC\4 -1- ABSTRACT. The thermal oxidation of an aromatic polyamide fibre, namel\' poly(m-xylylene adipamide) has been investigated. The volatile and non-volatile products of oxidation identified using T.L.C., H.P.L.C. and G.C.-M.S. include homologous series of monocarboxylic acids, dicarboxylic acids, n-alkyl amines, diamines and aldehydes. Furthermore, several aromatics, ketones and amides were also identified. Mechanisms for their derivation have been proposed which are based on oxidation reactions already established in polymer chemistry. These include a mechanism of ~ scission by an alkoxy radical thought to be responsible for the creation of the homologous series. MXD,6 fibres were also spun incorporating 100, 200 and 400ppm of a cobalt catalyst and the effect of the metal ions on the oxygen uptake of the fibres was investigated. The results show a consistent increase in the rate of oxygen uptake as the concentration of the cobalt is increased. Furthermore, T.G.A. oxidative degradation studies, conducted at isothermal temperatures in the solid state, show decreases in the activation energies associated with fibre oxidation with increased cobalt concentrations, implying the cobalt is a catalyst for oxidation. -
Polybenzimidazole Synthesis from Compounds with Sulfonate Ester Linkages
AN ABSTRACT OF THE THESIS OF Turgav Seckin for the degree of Master of Science in Chemistry presented on August 26, 1987 TITLE : Polybenzimidazole Synthesis Frog Comnounds with Sulfonate Ester Linkages Redacted for privacy Abstract approved : Dr. R.W. THIES This investigation of polybenzimidazole synthesis involvedthe two-stage low temperature solution polymerization of dialdehydes, One-step polycondensation of dialdehydes,two-stage melt polyconden- sation of diesters, and one-step solutionpolycondensation of diesters with 3,3'-diaminobenzidine. Dialdehyde or diester monomers were prepared which contained aromatic units whichwere hooked toget- her with sulfonate linkages. Polymerization of these monomers with 3,3'-diaminobenzidine resulted in moderate viscosities of0.4-0.8 dlg in DMSO at 19°C. The polybenzimidazoles obtained appear to be linear; most of them when tested immediatelyafter preparation, were largely soluble in certain acidicor dipolar approtic solvents. Films, obtained by dissolving the polymerin dipolar approtic solvents such as N,N-dimethylacetamideor N,N-dimethyl formamide, were flexible, clear, yellow to brown in color, and foldable depen- ding upon which monomers and which polymerization methodswere used. Polybenzimidazole Synthesis From Compounds with Sulfonate Ester Linkages by Turgay Seckin A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Master of Science Completed August 26, 1987 Commencement June 1988 APPROVED Redacted for privacy Professor of Chemistry in Charge ofMajor Redacted for privacy Chairman of Department of Chemistry Redacted for privacy Dean of G ad ate School Date thesis is prepared August 17, 1987 Thesis typed by Turgay Seckin To my family for their never failing love andsupport NE MUTLU TURKUM DIYENE ACKNOWLEDGEMENT I would like to thank Prof. -
Aim: to Prepare Block Copolymers of Methyl Methacrylate (MMA) and Styrene
Conducting A Reversible-Deactivation Radical Polymerization (RDRP) Aim: To Prepare Block Copolymers of Methyl Methacrylate (MMA) and Styrene. Polymers are ubiquitous in the modern world. They provide tremendous value because the chemical and physical properties of these materials are determined by the monomers that are used to put them together. One of the most powerful methods to construct polymers is radical-chain polymerization and this method is used in the commercial synthesis of polymers everyday. Methyl methacrylate is polymerized to form poly(methyl methacrylate) (PMMA) which is also known as acrylic glass or Plexiglas (about 2 billion pounds per year in the US). This material is lightweight, strong and durable. The polymer chains are rigid due to the tetrasubstituted carbon atom in the polymer backbone and they have excellent optical clarity. As a consequence, these materials are used in aircraft windows, glasses, skylights, signs and displays. Polystyrene (PS), which can also be synthesized from radical chain polymerization, has found extensive use as a material (also approximately 2 billion pounds per year in the US). One of the forms of PS, Styrofoam, is used extensively to make disposable cups, thermal insulation, and cushion for packaging. Scheme 1. Radical polymerization of methyl methacrylate or styrene. While there are extensive uses for these polymers, when synthesizing any material using a free-radical polymerization, samples are obtained with limited control over molecular weight and molecular weight distribution. New methods have been developed directly at Carnegie Mellon (https://www.cmu.edu/maty/) which lead to improved control in this process. This new method is a reversible-deactivation of the polymerization reaction where highly reactive radicals toggle back and forth between an active state, where the polymer chain is growing, and a dormant state, where the polymer chain is capped (Scheme 2). -
1 050929 Quiz 1 Introduction to Polymers 1) in Class We Discussed
050929 Quiz 1 Introduction to Polymers 1) In class we discussed a hierarchical categorization of the terms: macromolecule, polymer and plastics, in that plastics are polymers and macromolecules and polymers are macromolecules; but all macromolecules are not polymers and all polymers are not plastics. a) Give an example of a macromolecule that is not a polymer. b) Give an example of a polymer that is not a plastic. c) Define polymer. d) Define plastic. e) Define macromolecule. 2) In class we observed a simulation of a small polymer chain of 40 flexible steps. The chain was observed to explore configurational space. a) Explain what the phrase "explore configurational space" means. b) Consider the two ends of the chain to be tethered with a separation distance of about 6 extended steps. If temperature were increased would the chain ends push apart or pull together the tether points? Explain why. c) If one chain end is fixed in Cartesian space at x = 0, what are the limits on the x-axis for the other chain end as it explores configurational space? d) What is the average value of the position on the x-axis? dγ 3) Polymer melts are processed at high rates of strain, , in an extruder, injection molder, or dt calander. a) Sketch a typical plot of polymer viscosity versus rate of strain on a log-log plot showing the power-law region and the Newtonian plateau at low rates of strain. b) Explain using this plot why polymers are processed at high rates of strain. c) Using your own words propose a molecular model that could explain shear thinning in polymers. -
TEST - Alkenes, Alkadienes and Alkynes
Seminar_2 1. Nomenclature of unsaturated hydrocarbons 2. Polymerization 3. Reactions of the alkenes (table) 4. Reactions of the alkynes (table) TEST - Alkenes, alkadienes and alkynes. Polymerization • Give the names • Write the structural formula • Write all isomeric compounds • The processes explanation 1. NOMENCLATURE OF UNSATURATED HYDROCARBONS ALKENE NOMENCLATURE We give alkenes IUPAC names by replacing the -ane ending of the corresponding alkane with -ene . The two simplest alkenes are ethene and propene. Both are also well known by their common names ethylene and propylene. Ethylene is an acceptable synonym for ethene in the IUPAC system. Propylene, isobutylene, and other common names ending in -ylene are not acceptable IUPAC names. 1. The longest continuous chain that includes the double bond forms the base name of the alkene. 2. Chain is numbered in the direction that gives the doubly bonded carbons their lower numbers. 3. The locant (or numerical position) of only one of the doubly bonded carbons is specified in the name; it is understood that the other doubly bonded carbon must follow in sequence. 4. Carbon-carbon double bonds take precedence over alkyl groups and halogens in determining the main carbon chain and the direction in which it is numbered. 5. The common names of certain frequently encountered alkyl groups, such as isopropyl and tert-butyl, are acceptable in the IUPAC system. Three alkenyl groups--vinyl, allyl, and isopropenyl--are treated the same way: 6. When a CH 2 group is doubly bonded to a ring, the prefix methylene is added to the name of the ring: 7. Cycloalkenes and their derivatives are named by adapting cycloalkane terminology to the principles of alkene nomenclature: No locants are needed in the absence of substituents; it is understood that the double bond connects C-1 and C 2. -
Controlled Free Radical Polymerization of Styrene Initiated by a [BPO-Polystyrene-(4-Acetamido-TEMPO)] Macroinitiator
Die Angewandte Makromolekulare Chemie 265 (1999) 69–74 (Nr. 4630) 69 Controlled free radical polymerization of styrene initiated by a [BPO-polystyrene-(4-acetamido-TEMPO)] macroinitiator Chang Hun Han, So¨ren Butz, Gudrun Schmidt-Naake* Institut fu¨r Technische Chemie, TU Clausthal, Erzstr. 18, 38678 Clausthal-Zellerfeld, Germany (Received 15 October 1998) SUMMARY: The bulk polymerization of styrene at 1258C was studied using a [BPO-polystyrene-(4-acet- amido-TEMPO)] macroinitiator synthesized by a styrene polymerization in the presence of 4-acetamido- 2,2,6,6-tetramethylpiperidine-N-oxyl (4-acetamido-TEMPO) and benzoyl peroxide (BPO). The rates of poly- merization were independent of the initial macroinitiator concentration and they were very similar to that for the thermal autopolymerization of styrene. Additionally, different types of N-oxyls did not have any effect on the polymerization rate. The number-average molecular weights (Mn) of the obtained polymers agreed very well with theoretical predictions, deviations were observed only at low macroinitiator concentrations. Increasing macroinitiator concentrations resulted in lower magnitudes of the growing molecular weights and reduced polydispersities (Mw/Mn) at the initial stage of the polymerization. The concentration of the polymer chains was calculated, and it was recognized that the concentration of polymer chains increased during the polymerization as a result of an additional radical formation due to the thermal self-initiation of styrene. This thermal self-initiation could be proved qualitatively by the addition of N-oxyl to a macroinitiator polymeriza- tion system. ZUSAMMENFASSUNG: Ausgehend von [BPO-Polystyrol-(4-Acetamido-TEMPO)]-Makroinitiatoren wurde die Substanzpolymerisation von Styrol bei 1258C untersucht. Die Polymerisationsgeschwindigkeit war unabha¨ngig von der eingesetzten Makroinitiator-Konzentration und stimmte im Rahmen der Meß- genauigkeit mit der der thermisch initiierten Autopolymerisation von Styrol u¨berein. -
Azo Polymerization Initiators Comprehensive Catalog
Azo Polymerization Initiators Comprehensive Catalog FUJIFILM Wako Pure Chemical Corporation 4-1 Nihonbashi Honcho 2-Chome, Japan Chuo-Ku, Tokyo 103-0023, Japan TEL+81-3-3244-0305 FUJIFILM Wako Chemicals U.S.A. Corporation 1600 Bellwood Road Richmond, USA VA 23237, U.S.A. TEL+1-804-271-7677 FUJIFILM Wako Chemicals Europe GmbH Fuggerstrasse 12 D-41468 Neuss GERMANY Germany TEL+49-2131-311-0 Wako Chemicals (Shanghai) Co., Ltd. C1-C2, 26F, Junyao International Plaza, China 789 Zhaojiabang Road, Shanghai 200032, China TEL+86-21-6407-0511 Specialty Chemicals Web Site http://www.wako-chem.co.jp/kaseihin_en/ 180401 K2 SI 01 Introduction/What is Radical Polymerization? What is Azo Polymerization Initiator? Radical Formation Mechanism 01 INDEX 01 Introduction/What is Radical Polymerization? P1 07 Detailed Explanations 1. Azo Nitrile P11-14 What are Azo Polymerization Initiator? What are Azo Polymerization Initiator? Radical Formation Mechanism P2 2. Azo Ester P15-16 An azo polymerization initiator is a compound having an azo group (R-N=N-R’), which decomposes with heat 3. Azo Amide P17-18 Characteristics of Azo Polymerization Initiators and Comparison with Peroxides P3 02 4. Azo Imidazoline P19-20 and/or light, and forms carbon radical. The formed carbon radical is excellent in reactivity, and progresses polym- Examples of radical reactions using Azo Polymerization Initiators P4 5. Azo Amidine P21-22 erization and halogenation reactions of different types of vinyl monomers. 03 Selection Guide P5-6 6. Macro Azo Initiator P23-26 04 Decomposition