Living/Controlled Radical Polymerizations in Dispersed Phase Systems
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2 a Primer on Polymer Colloids: Structure, Synthesis and Colloidal Stability
A. Al Shboul, F. Pierre, and J. P. Claverie 2 A primer on polymer colloids: structure, synthesis and colloidal stability 2.1 Introduction A colloid is a dispersion of very fine objects in a fluid [1]. These objects can be solids, liquids or gas, and the corresponding colloidal dispersion is then referred to as sus- pension, emulsion or foam. Colloids possess unique characteristics. For example, as their size is smaller than the wavelength of light, they scatter light. They also offer a large interfacial surface area, meaning that interfacial phenomena are of paramount importance in these dispersions. The weight of each dispersed particle being small, gravity and buoyancy forces are not sufficient to counteract the thermal random mo- tion of the particle, named Brownian motion (in tribute to the 19th century botanist Robert Brown who first characterized it). The particles do not remain in a dispersed state indefinitely: they will sooner or later aggregate (phase separation). Thus, thecol- loidal state is in general metastable and colloidal stability is one of the key features to take into account when working with colloids. Among all colloids, the polymer colloid family is one of the most widely inves- tigated [2]. Polymer colloids are used for a large number of applications, ranging from coatings, adhesives, inks, impact modifiers, drug-delivery vehicles, etc. The particles range in size from about 10 nm to 1 000 nm (1 μm) in diameter. They are usually spherical, but numerous other shapes have been observed. Polymer colloids are not uncommon in nature. For example, natural rubber latex, the secretion of the Hevea brasiliensis tree, is in fact a dispersion of polyisoprene nanoparticles in wa- ter. -
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 -
„Polymer-Dispersionen“
„Polymer-Dispersionen“ Klaus Tauer Definitions Meaning & properties of polymer dispersions Preparation of polymer dispersions Polymer Dispersions Polymer: any of a class of natural or synthetic substances composed of very large molecules, called macromolecules, that are multiples of simpler chemical units called monomers. Polymers make up also many of the materials in living organisms, including, for example, proteins, cellulose, and nucleic acids. Dispersion: (physical chemistry) a special form of a colloid: i.e. very fine particles (of a second phase) dispersed in a continuous medium the most popular / famous / best-known case of a polymer dispersion is a LATEX a latex is produced by heterophase polymerization, where the most important technique is emulsion polymerization *) *) *) 1 DM = 1.95583 € Molecular Composition polymer dispersionen: high concentration of polymer with low viscosity thickener (BASF AG, Ludwigshafen) Virtual EASE 2003/1 „Thickening agent“ Sterocoll is an acidic aqueous polymer dispersion containing polymer particles rich in caroxylic acid groups. It is used as thickening agent. First the polymer dispersion is diluted with water to lower the polymer content from 30 % to 5 %. It is still a white liquid having low viscosity. By addition of a small amount of an aqueous sodium hydroxide solution the pH is increased and the caroxylic acid groups are negatively charged. This makes the polymer particles soluble in water and a polymer solution is formed. At the same time the viscosity strongly increases due to the unfolding of the polymer molecules. At the end a clear gel is obtained. important application properties: viscosity viscosity-psd dilatancy (BASF AG, Ludwigshafen) „Dilatancy“ Dilatancy is a rheological phenomenon. -
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. -
Initiator Systems Effect on Particle Coagulation and Particle Size Distribution in One-Step Emulsion Polymerization of Styrene
polymers Article Initiator Systems Effect on Particle Coagulation and Particle Size Distribution in One-Step Emulsion Polymerization of Styrene Baijun Liu 1, Yajun Wang 1, Mingyao Zhang 1,* and Huixuan Zhang 1,2 1 School of Chemical Engineering, Changchun University of Technology, Changchun 130012, China; [email protected] (B.L.); [email protected] (Y.W.); [email protected] (H.Z.) 2 Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China * Correspondence: [email protected]; Tel.: +86-431-8571-6465 Academic Editor: Haruma Kawaguchi Received: 6 December 2015; Accepted: 15 February 2016; Published: 19 February 2016 Abstract: Particle coagulation is a facile approach to produce large-scale polymer latex particles. This approach has been widely used in academic and industrial research owing to its higher polymerization rate and one-step polymerization process. Our work was motivated to control the extent (or time) of particle coagulation. Depending on reaction parameters, particle coagulation is also able to produce narrowly dispersed latex particles. In this study, a series of experiments were performed to investigate the role of the initiator system in determining particle coagulation and particle size distribution. Under the optimal initiation conditions, such as cationic initiator systems or higher reaction temperature, the time of particle coagulation would be advanced to particle nucleation period, leading to the narrowly dispersed polymer latex particles. By using a combination of the Smoluchowski equation and the electrostatic stability theory, the relationship between the particle size distribution and particle coagulation was established: the earlier the particle coagulation, the narrower the particle size distribution, while the larger the extent of particle coagulation, the larger the average particle size. -
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 ........................................................................................................... -
Acrylamide, Sodium Acrylate Polymer (Cas No
ACRYLAMIDE/SODIUM ACRYLATE COPOLYMER (CAS NO. 25085‐02‐3) ACRYLAMIDE, SODIUM ACRYLATE POLYMER (CAS NO. 25987‐30‐8) 2‐PROPENOIC ACID, POTASSIUM SALT, POLYMER WITH 2‐PROPENAMIDE (CAS NO. 31212‐13‐2) SILICONE BASED EMULSION NEUTRALISED POLYACRYLIC BASED STABILIZER (NO CAS NO.) This group contains a sodium salt of a polymer consisting of acrylic acid, methacrylic acid or one of their simple esters and three similar polymers. They are expected to have similar environmental concerns and have consequently been assessed as a group. Information provided in this dossier is based on acrylamide/sodium acrylate copolymer (CAS No. 25085‐02‐3). This dossier on acrylamide/sodium acrylate copolymer and similar polymers presents the most critical studies pertinent to the risk assessment of these polymers in their use in drilling muds. This dossier does not represent an exhaustive or critical review of all available data. Where possible, study quality was evaluated using the Klimisch scoring system (Klimisch et al., 1997). Screening Assessment Conclusion – Acrylamide/sodium acrylate copolymer, acrylamide, sodium acrylate polymer and 2‐propenoic acid, potassium salt, polymer with 2‐propenamide are polymers of low concern. Therefore, these polymers and the other similar polymer in this group are classified as tier 1 chemicals and require a hazard assessment only. 1. BACKGROUND Acrylamide/sodium acrylate copolymer is a sodium salt of a polymer consisting of acrylic acid, methacrylic acid or one of their simple esters. Acrylates are a family of polymers which are a type of vinyl polymer. Synthetic chemicals used in the manufacture of plastics, paint formulations and other products. Acrylate copolymer is a general term for copolymers of two or more monomers consisting of acrylic acid, methacrylic acid or one of their simple esters. -
High Temperature, Living Polymerization of Ethylene by a Sterically-Demanding Nickel(II) Α-Diimine Catalyst
polymers Article High Temperature, Living Polymerization of Ethylene by a Sterically-Demanding Nickel(II) α-Diimine Catalyst Lauren A. Brown, W. Curtis Anderson Jr., Nolan E. Mitchell, Kevin R. Gmernicki and Brian K. Long * ID Department of Chemistry, University of Tennessee, Knoxville, TN 37996, USA; [email protected] (L.A.B.); [email protected] (W.C.A.J.); [email protected] (N.E.M.); [email protected] (K.R.G.) * Correspondence: [email protected]; Tel.: +1-865-974-5664 Received: 15 December 2017; Accepted: 27 December 2017; Published: 2 January 2018 Abstract: Catalysts that employ late transition-metals, namely Ni and Pd, have been extensively studied for olefin polymerizations, co-polymerizations, and for the synthesis of advanced polymeric structures, such as block co-polymers. Unfortunately, many of these catalysts often exhibit poor thermal stability and/or non-living polymerization behavior that limits their ability to access tailored polymer structures. Due to this, the development of catalysts that display controlled/living behavior at elevated temperatures is vital. In this manuscript, we describe a Ni α-diimine complex that is capable of polymerizing ethylene in a living manner at temperatures as high as 75 ◦C, which is one of the highest temperatures reported for the living polymerization of ethylene by a late transition metal-based catalyst. Furthermore, we will demonstrate that this catalyst’s living behavior is not dependent on the presence of monomer, and that it can be exploited to access polyethylene-based block co-polymers. Keywords: polyethylene; living polymerization; nickel α-diimine; catalysis 1. Introduction Controlled/living polymerizations offer a precise means by which polymer structure, co-monomer incorporation levels, and even regio- and stereoselectivity can be tailored [1–7]. -
Poly( Ethylene-Co-Methyl Acrylate)-Solvent- Cosolvent Phase Behaviour at High Pressures
Poly( ethylene-co-methyl acrylate)-solvent- cosolvent phase behaviour at high pressures Melchior A. Meilchen, Bruce M. Hasch, Sang-Ho Lee and Mark A. McHugh* Department of Chemical Engineering, Johns Hopkins University, Baltimore, MD 21278, USA (Received 5 April 7991; accepted 75 July 1997 ) Cloud-point data to 160°C and 2000 bar are presented showing the effect of cosolvents on the phase behaviour of poly(ethylene-co-methyl acrylate) (EMA) (64 mo1%/36 mol%) with propane and chlorodifluoromethane (F22). Ethanol shifts the EMA-propane cloud-point curves to lower temperatures and pressures, but above _ 10 wt% ethanol, the copolymer becomes insoluble. Up to 40 wt% acetone monotonically shifts the EMA-propane cloud-point curves to lower temperatures and pressures. Acetone and ethanol both shift the cloud-point curves of EMA-F22 mixtures in the same monotonic manner for cosolvent concentrations of up to 40 wt%. (Keywords: copolymer; cosolvent; high pressures) INTRODUCTION or diethyl ether, so it is necessary to operate at elevated temperatures and pressures to dissolve high molecular Within the past 20 years there has been a great deal of weight polystyrene in either solvent. Adding acetone to effort invested in trying to understand and model the PS-diethyl ether mixtures monotonically reduces the solubility behaviour of polar polymers in liquid cosolvent pressure needed at a given temperature to obtain a single mixtures’-9. Polymer solubility is usually related to phase. whether the cosolvent preferentially solvates or adsorbs There has also been a number of viscometric and light to certain segments of the polymer chain as determined scattering studies on the solution behaviour of polar by light scattering, viscosity measurements or cloud- copolymers in liquid cosolvent mixtures’4*‘5. -
Synthesis of Polypeptides by Ring-Opening Polymerization of A-Amino Acid N-Carboxyanhydrides
Top Curr Chem (2011) DOI: 10.1007/128_2011_173 # Springer-Verlag Berlin Heidelberg 2011 Synthesis of Polypeptides by Ring-Opening Polymerization of a-Amino Acid N-Carboxyanhydrides Jianjun Cheng and Timothy J. Deming Abstract This chapter summarizes methods for the synthesis of polypeptides by ring-opening polymerization. Traditional and recently improved methods used to polymerize a-amino acid N-carboxyanhydrides (NCAs) for the synthesis of homo- polypeptides are described. Use of these methods and strategies for the preparation of block copolypeptides and side-chain-functionalized polypeptides are also pre- sented, as well as an analysis of the synthetic scope of different approaches. Finally, issues relating to obtaining highly functional polypeptides in pure form are detailed. Keywords Amino acid Á Block copolymer Á N-Carboxyanhydride Á Polymerization Á Polypeptide Contents 1 Introduction 2 Polypeptide Synthesis Using NCAs 2.1 Conventional Methods 2.2 Transition Metal Initiators 2.3 Recent Developments 3 Copolypeptide and Functional Polypeptide Synthesis via NCA Polymerization 3.1 Block Copolypeptides 3.2 Side-Chain-Functionalized Polypeptides 4 Polypeptide Deprotection and Purification 5 Conclusions and Future Prospects References J. Cheng Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Champaign, IL 61801, USA T.J. Deming (*) Department of Bioengineering, University of California, Los Angeles, CA 90095, USA e-mail: [email protected] J. Cheng and T.J. Deming Abbreviations AM Activated -
7: Source-Based Nomenclature for Copolymers (1985)
7: Source-Based Nomenclature for Copolymers (1985) PREAMBLE Copolymers have gained considerable importance both in scientific research and in industrial applications. A consistent and clearly defined system for naming these polymers would, therefore, be of great utility. The nomenclature proposals presented here are intended to serve this purpose by setting forth a system for designating the types of monomeric-unit sequence arrangements in copolymer molecules. In principle, a comprehensive structure-based system of naming copolymers would be desirable. However, such a system presupposes a knowledge of the structural identity of all the constitutional units as well as their sequential arrangements within the polymer molecules; this information is rarely available for the synthetic polymers encountered in practice. For this reason, the proposals presented in this Report embody an essentially source-based nomenclature system. Application of this system should not discourage the use of structure-based nomenclature whenever the copolymer structure is fully known and is amenable to treatment by the rules for single-strand polymers [1, 2]. Further, an attempt has been made to maintain consistency, as far as possible, with the abbreviated nomenclature of synthetic polypeptides published by the IUPAC-IUB Commission on Biochemical Nomenclature [3]. It is intended that the present nomenclature system supersede the previous recommendations published in 1952 [4]. BASIC CONCEPT The nomenclature system presented here is designed for copolymers. By definition, copolymers are polymers that are derived from more than one species of monomer [5]. Various classes of copolymers are discussed, which are based on the characteristic sequence arrangements of the monomeric units within the copolymer molecules. -
Reversible Deactivation Radical Polymerization: State-Of-The-Art in 2017
Chapter 1 Reversible Deactivation Radical Polymerization: State-of-the-Art in 2017 Sivaprakash Shanmugam and Krzysztof Matyjaszewski* Center for Macromolecular Engineering, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States *E-mail: [email protected]. This chapter highlights the current advancements in reversible-deactivation radical polymerization (RDRP) with a specifc focus on atom transfer radical polymerization (ATRP). The chapter begins with highlighting the termination pathways for acrylates radicals that were recently explored via RDRP techniques. This led to a better understanding of the catalytic radical termination (CRT) in ATRP for acrylate radicals. The designed new ligands for ATRP also enabled the suppression of CRT and increased chain end functionality. In addition, further mechanistic understandings of SARA-ATRP with Cu0 activation and comproportionation were studied using model reactions with different ligands and alkyl halide initiators. Another focus of RDRP in recent years has been on systems that are regulated by external stimuli such as light, Downloaded via CARNEGIE MELLON UNIV on August 17, 2020 at 15:07:44 (UTC). electricity, mechanical forces and chemical redox reactions. Recent advancements made in RDRP in the feld of complex See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles. polymeric architectures, organic-inorganic hybrid materials and bioconjugates have also been summarized. Introduction The overarching goal of this chapter is to provide an overall summary of the recent achievements in reversible-deactivation radical polymerization (RDRP), primarily in atom transfer radical polymerization (ATRP), and also in reversible addition-fragmentation chain transfer (RAFT) polymerization, tellurium mediated © 2018 American Chemical Society Matyjaszewski et al.; Reversible Deactivation Radical Polymerization: Mechanisms and Synthetic Methodologies ACS Symposium Series; American Chemical Society: Washington, DC, 2018.