Poly(Sodium Acrylate)-Based Antibacterial Nanocomposite Materials
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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 -
Acrylamide Polymerization — a Practical Approach
electrophoresis tech note 1156 Acrylamide Polymerization — A Practical Approach Paul Menter, Bio-Rad Laboratories, 2000 Alfred Nobel Drive, Polyacrylamide Gel Polymerization Hercules, CA 94547 USA AcrylamideBis Polyacrylamide Introduction The unparalleled resolution and flexibility possible with CH2 CH + CH2 CH CH2 CH CH2 CH CH2 CH polyacrylamide gel electrophoresis (PAGE) has led to its CO CO CO CO CO widespread use for the separation of proteins and nucleic NH2 NH NH2 NH2 NH acids. Gel porosity can be varied over a wide range to meet CH2 CH2 specific separation requirements. Electrophoresis gels and NH NH NH NH buffers can be chosen to provide separation on the basis of CO 2 2 CO CO C O charge, size, or a combination of charge and size. CH2 CH CH2 CH CH2 CH CH2 CH The key to mastering this powerful technique lies in the polymerization process itself. By understanding the important Purity of Gel-Forming Reagents parameters, and following a few simple guidelines, the novice Acrylamide can become proficient and the experienced user can optimize Gel-forming reagents include the monomers, acrylamide and bis, separations even further. as well as the initiators, usually ammonium persulfate and TEMED or, occasionally, riboflavin and TEMED. On a molar This bulletin takes a practical approach to the preparation of basis, acrylamide is by far the most abundant component in the polyacrylamide gels. Its purpose is to provide the information monomer solution. As a result, acrylamide may be the primary required to achieve reproducible, controllable polymerization. source of interfering contaminants (Dirksen and Chrambach For those users interested only in the “bare essentials,” the 1972). -
Dispersion Polymerization of Anionic Polyacrylamide in an Aqueous Salt Medium
410 Pet.Sci.(2010)7:410-415 DOI 10.1007/s12182-010-0086-9 Dispersion polymerization of anionic polyacrylamide in an aqueous salt medium Lu Jiao, Peng Bo , Li Mingyuan, Lin Meiqin and Dong Zhaoxia Enhanced Oil Recovery Research Center, China University of Petroleum, Beijing 102249, China © China University of Petroleum (Beijing) and Springer-Verlag Berlin Heidelberg 2010 Abstract: Anionic polyacrylamide dispersions were prepared by dispersion polymerization in an aqueous salt medium, using acrylamide(AM) and acrylic acid(AA) as monomers and anionic polyelectrolytes as stabilizer. Effects of salt concentration, and molecular weight and concentration of stabilizers on the stability of the dispersions were investigated using a HAAKE rheometer and optical microscopy. The results showed that stable anionic polyacrylamide dispersions, consisting of smooth, spherical, polydisperse particles, could be obtained under the conditions of salt concentration ranging from 26 wt% to 30 wt%, concentration of stabilizers from 1.2 wt% to 1.8 wt%, and intrinsic viscosity of stabilizers from 2.98 dL·g-1 to 3.74 dL·g-1. The apparent viscosity of the stable dispersions changed very little with the shear rate, showing Newton fl uid behavior. Key words: Dispersion polymerization, aqueous salt medium, stability, micromorphology, apparent viscosity 1 Introduction chain length during polymerization. The precipitated polymers form spherical micro-particles through aggregation Polyacrylamide (PAM) is an important water-soluble and the particles are suspended in the medium by the polymer. It can be used as a flocculant for water disposal, adsorption of stabilizer. There are several advantages of strength additives for paper manufacture, oil displacement dispersion polymerization, such as no secondary pollution, agents for enhanced oil recovery, and so on (Yan, 1998). -
Optimizing Chemically Enhanced Primary Treatment Processes for Simultaneous Carbon Redirection and Phosphorus Removal
water Article Optimizing Chemically Enhanced Primary Treatment Processes for Simultaneous Carbon Redirection and Phosphorus Removal Tianchen Dong 1, Wudneh Ayele Shewa 1, Kyle Murray 2 and Martha Dagnew 1,* 1 Department of Civil and Environmental Engineering, Western University, 1151 Richmond Street, London, ON N6A 3K7, Canada; [email protected] (T.D.); [email protected] (W.A.S.) 2 City of London, 300 Dufferin Avenue, London, ON N6B 1Z2, Canada; [email protected] * Correspondence: [email protected]; Tel.: +1-519-661-2111 (ext. 87427) Received: 25 February 2019; Accepted: 13 March 2019; Published: 16 March 2019 Abstract: There has been increased interest towards maximizing wastewater energy recovery by enhancing the carbon captured through the primary treatment process such as chemically enhanced primary treatment (CEPT). This research was conducted to optimize the CEPT performance in terms of redirection of carbon and nutrients in both bench- and full-scale operations. In order to improve the CEPT process, the performance of ferric chloride and seven types of polymers were evaluated through jar testing. The optimal coagulant (15 mg/L ferric chloride) and flocculant (0.5 mg/L poly aluminum chloride (PACl)) combination achieved total COD, soluble COD, total suspended solids (TSS), and total phosphorus (TP) removal efficiencies of 76, 58, 89, and 84, respectively, in a full-scale primary clarifier operation. In doing so the organic matter and phosphorus were concentrated in CEPT sludge, making them available for recovery. Furthermore, the relationship between influent characteristics and removal rates under varying operating conditions was investigated. It was found that soluble COD removal appeared to be season-dependent, and TSS removals were independent of influent TSS concentrations in all scenarios. -
Chitosan Based Hydrogels and Their Applications for Drug Delivery in Wound Dressings: a Review T ⁎ Hamid Hamedi, Sara Moradi, Samuel M
Carbohydrate Polymers 199 (2018) 445–460 Contents lists available at ScienceDirect Carbohydrate Polymers journal homepage: www.elsevier.com/locate/carbpol Chitosan based hydrogels and their applications for drug delivery in wound dressings: A review T ⁎ Hamid Hamedi, Sara Moradi, Samuel M. Hudson, Alan E. Tonelli Textile Engineering Chemistry and Science, Fiber & Polymer Science Program, College of Textiles, North Carolina State University, Raleigh, North Carolina 27606-8301, United States ARTICLE INFO ABSTRACT Keywords: Advanced development of chitosan hydrogels has led to new drug delivery systems that can release their active Chitosan hydrogel ingredients in response to environmental stimuli. This review considers more recent investigation of chitosan Wound dressing hydrogel preparations and the application of these preparations for drug delivery in wound dressings. Drug delivery Applications and structural characteristics of different types of active ingredients, such as growth factors, na- Growth factor noparticles, nanostructures, and drug loaded chitosan hydrogels are summarized. Nanoparticles 1. Introduction 2012), pullulan (Li et al., 2011; Wong et al., 2011) and/or synthetic polymers like polyvinyl alcohol (Kokabi et al., 2007; Razzak, 2001; Hydrogels are three-dimensional, cross-linked networks which can Yang et al., 2008), polyacrylamide (Ezra et al., 2009; Risbud & Bhonde, absorb and retain significant amounts of water, without dissolving or 2000; Rosiak et al., 1983) and polyethylene glycol (Ajji et al., 2005; losing their three dimensional structures (Ahmed, 2015; Kashyap, 2005; Gupta et al., 2011; Lih et al., 2012) form hydrogels. Y.B. et al., 2008). The gelation and biodegradation are two key factors Hydrogels are classified into two categories: chemical or permanent affecting the fate of cells (Li et al., 2012). -
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. -
High Performance of Chitosan-Co-Polyacrylamide-Tio2 Crosslinked Glutaraldehyde Hydrogel As Soil Conditioner for Soybean Plant (Glycine Max)
SOIL SCIENCE ANNUAL 2020, 71(3), 194–204 https://doi.org/10.37501/soilsa/125847 High Performance of Chitosan-co-Polyacrylamide-TiO2 Crosslinked Glutaraldehyde Hydrogel as Soil Conditioner for Soybean Plant (Glycine max) Halimahtussaddiyah Ritonga1, Muhammad Ihram Basri1, Fransiskus S. Rembon2, La Ode Ahmad Nur Ramadhan1, Muhammad Nurdin1* 1 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Halu Oleo, Kendari 93232, Southeast Sulawesi, Indonesia 2 Department of Soil Science, Faculty of Agriculture, Universitas Halu Oleo, Kendari 93232, Southeast Sulawesi, Indonesia * Prof. Muhammad Nurdin, Ph.D, [email protected], ORCID ID: https://orcid.org/0000-0002-6727-9283 Abstract Received: 10.01.2020 Research on hydrogels as soil conditioners has been developed based on hydrogels copolymerized Accepted: 29.07.2020 with composite materials in the form of chitosan and TiO2 to overcome low physical properties and Associated editor: J. Antonkiewicz low swelling of polyacrylamide. The aims of the study are synthesis, characterization, application of hydrogels, and determination of the physical and chemical properties of soil and the growth of soy- bean plants. Synthesis of chitosan-co-polyacrylamide-TiO2 crosslinked glutaraldehyde hydrogel was Keywords prepared by the chemical crosslinking method. The characterization of hydrogel was performed by using Fourier Transform Infra-Red (FTIR) and Scanning Electron Microscope (SEM). FTIR spectrum Composite shows the functional groups of chitosan co-polyacrylamide-TiO2 crosslinked glutaraldehyde which –1 –1 –1 –1 Hydrogel includes OH functional groups (3408.22 cm ), NH (1602.85 cm ), C=O (1502 cm ), CN (1600.92 cm ), –1 Soil conditioner and Ti-O (619.15 cm ). The SEM image shows the formation of pores and cavities in the hydrogel. -
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. -
A Guide to Using Polyacrylamide (PAM) Polymers for Control of Irrigation Run-Off on the Central Coast Michael Cahn, Irrigation A
A Guide to Using Polyacrylamide (PAM) Polymers for Control of Irrigation Run-off on the Central Coast Michael Cahn, Irrigation and Water Resources Advisor, Monterey County Introduction Federal and state water quality regulations require that growers implement management practices to minimize impairments to surface and ground water quality. Although many farmers are currently using recommended practices such as drip irrigation, cover crops, and integrated pest management to reduce the impacts of agriculture on water quality, additional management tools could help achieve more dramatic improvements to water quality. Irrigation run-off can often be difficult to control on soils with low infiltration capacity such as poorly aggregated sandy soils, or soils susceptible to crusting. Sediments suspended in irrigation tail water carry adsorbed nutrients and some classes of pesticides such as pyrethroids. Nitrogen, phosphorus, and several classes of pesticides have been determined to impair the quality of surface water on the Central Coast. The use of practices such as retention ponds and drip irrigation can significantly control irrigation tail water, but these practices can be expensive and may not be suited for all crops and farms. Baby greens, for example, are typically irrigated with overhead sprinklers, and although many cool season vegetables can be grown with drip, almost all of these crops are established with overhead sprinklers during the first 2 to 4 weeks of stand establishment. Research studies conducted since 2003 on the Central Coast have repeatedly demonstrated that polyacrylamide (PAM), a chemical polymer can significantly reduce sediment, nutrient, and pesticide concentrations in irrigation run-off from sprinkler and furrow systems. -
Solution Polymerization of Acrylic Acid Initiated by Redox Couple Na-PS/Na-MBS: Kinetic Model and Transition to Continuous Process
processes Article Solution Polymerization of Acrylic Acid Initiated by Redox Couple Na-PS/Na-MBS: Kinetic Model and Transition to Continuous Process Federico Florit , Paola Rodrigues Bassam , Alberto Cesana and Giuseppe Storti * Politecnico di Milano, Dipartimento di Chimica, Materiali e Ingegneria Chimica “G. Natta”, Piazza Leonardo da Vinci, 32, 20133 Milano, Italy; federico.fl[email protected] (F.F.); [email protected] (P.R.B.); [email protected] (A.C.) * Correspondence: [email protected] Received: 28 May 2020; Accepted: 14 July 2020; Published: 16 July 2020 Abstract: This work aims at modeling in detail the polymerization of non-ionized acrylic acid in aqueous solution. The population balances required to evaluate the main average properties of molecular weight were solved by the method of moments. The polymerization process considered is initiated by a persulfate/metabisulfate redox couple and, in particular, the kinetic scheme considers the possible formation of mid-chain radicals and transfer reactions. The proposed model is validated using experimental data collected in a laboratory-scale discontinuous reactor. The developed kinetic model is then used to intensify the discontinuous process by shifting it to a continuous one based on a tubular reactor with intermediate feeds. One of the experimental runs is selected to show how the proposed model can be used to assess the transition from batch to continuous process and allow faster scale-up to industrial scale using a literature approach. Keywords: Poly(acrylic acid); free-radical polymerization; reaction model; process intensification; semi-batch to continuous 1. Introduction Poly(acrylic acid) (PAA) is a widely produced polymer with a growing, global annual production of 1.58 109 kg as of 2008 [1] and with applications in many industrial sectors.