Polymer Chemistry Commons^™

Synthesis, Reactions, And Applications Of Bis-Ortho-Diynyl Arene (Boda) Monomers, Polymers, And Derivatives, Mark Perpall

All Dissertations

Bis-ortho-diynyl arenes (BODA) monomers contain two arenediyne functional groups with variable functionality at both the linker group, X, and the alkyne terminal group, R. These arenediyne moieties undergo thermal Bergman reactions to cycloaromatize to naphthyl diradical species. The inclusion of two of these arenediyne functionalities allows the polymer to grow without losing processability and solubility as most aromatic polymers do. The second functionality acts as a solubilizing group until all functionalities are consumed in the fully cured network polymer.
When heated above 800 °C, BODA polymer converts to a high-yield glassy carbon material. This work has been extended …

Surge Of Green: A Sustainable Approach To Conductive Polymers, Bethany Masten

Undergraduate Review

No abstract provided.

Synthesis And Characterization Of Arylmethyl Sulfone Dendrimers And Hyperbranched Poly (Phenylene Sulfide) / Poly (Sulfone), Qiuxia Zhao

Seton Hall University Dissertations and Theses (ETDs)

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Incompressible And Compressible Boundary Layers On A Fibre In The Melt Spinning Process, John Harding

Doctoral

This thesis seeks to investigate shear stress on and heat transfer from the surface of a fibre in the industrial process of melt spinning. Melt spinning is the process whereby molten polymer materials are extruded through the holes of a device known as a spinneret to create continuous filaments of polymer. Fibres manufactured in this way are used in applications as diverse as fashion and clothing, to telecommunications. The magnitude ofthe shear stress on the fibre surface, and also the rate of heat transfer from the fibre to the surrounding environment are of major importance to the overall quality of …

A Novel Tio2 / Pvc Layer For Use In A Photoelectrochemical Cell, Faiza Touati, John Cassidy, Kevin Mcguigan

Articles

A novel method of coating titanium dioxide on a glassy carbon electrode as a polyvinylchloride composite , is described. On illumination , there is an enhanced voltammetric current at this TiO2/PVC composite in aqueous formic acid solution. This electrode is used as the basis of a formic acid fuel cell where oxygen is reduced at a platinum cathode. The system yields 100 cm-2 for 0.01 mol dm-3 HCOOH in 0.1 mol dm-3 NaOH under illumination from a 150 W xenon lamp. The current without illumination is 0.5 cm-2.

Synthesis And Characterization Of Highly Conductive Polypyrrole And Polypyrrole/Lignosulfonate/Graphite Composites, Aopeau Imvittaya

Theses and Dissertations

Polypyrrole (PPy) is one of the conductive polymers frequently used in commercial applications, mainly due to its long-term stability and the possibility of forming homopolymers or composites with optimal properties. Polypyrroles were prepared by the chemical polymerization of pyrrole using various methods. The effects of several parameters such as oxidant, dopant type, additives and reaction conditions on the properties of PPy were investigated. In addition, PPy/graphite composites were prepared because graphite is highly conductive and effectively incorporated into the polymer matrix during the polymerization. The amount of graphite in the composite was varied to determine the maximimum conductivity achievable in …

Polyaniline And Its Derivatives For Environmental Analysis., Atogho Jude Abia

Electronic Theses and Dissertations

Electrooxidation has been used to deposit thin film polyaniline as well as its derivative - thin film poly (ortho-phenylenediamine) (POPD) and poly (meta-phenylenediamine) (PMPD) on carbon electrodes, which are subsequently used to monitor the environmental heavy metal ions (Hg²⁺, Pb²⁺ ,Cd²⁺) through a rather unusual "blocking" of anodic stripping for these metals. Using Hg²⁺ as a model, its cyclic voltammogram for a modified glassy carbon electrode with the resultant polymer shows an enhanced cathodic peak that increases linearly with the analyte ion concentration. POPD also exhibits unique selective detection for organic species. Acetaminophen and …

Investigations Of Poly[(Styrene-Co-P-Methylstyrene)-Risobutylene- R-(Styrene-Co-P-Methylstyrene)] And Poly[(Acrylic Acid)-5-Styrene-Jb-Is0butylene-5-Styrene-Jb-(Acrylic Acid)], James Grabill Kopchick

Dissertations

The pMe study was conducted to understand the morphological and physical property changes that occur as the ratio of pMe to styrene is increased, effectively increasing the aliphatic units. By the introduction of pMe, the interface region becomes more blended/compatible as the pMe migrates to the interface. These pMe groups are theorized in effect to create multiple ‘anchors’ to distribute the loads experienced at the interface more effectively creating a synergistic effect on the final properties of the copolymers. The primary goals of the pentablock study were the characterization of unique membranes as related to …

Isothermal Titration Calorimetry And Transmission Electron Microscopy Of Main-Chain Viologen Polymer Containing Bromide As Counerions, Pradip K. Bhowmik, Marcos A. Cheney, Haesook Han, Longzhou Ma

Transmission Electron Microscope

Polyelectrolytes are an important class of macromolecules that contain dissociable ionic groups. When introduced into polar solvent, usually the universal solvent water, dissociation takes place so that electrically charged macromolecule is suspended in solution. The electrostatic interaction is operative between ionized groups inside the macromolecule, between the macromolecules, between the counterions, and between the macromolecule and counterion. Since this interaction is characterized by its long-range nature, the solution exhibits various interesting properties including the polyelectrolyte behavior very different from solutions of neutral polymers.

Excimer Emission From Cathode Boundary Layer Discharges, Mohamed Moselhy, Karl H. Schoenbach

Bioelectrics Publications

The excimer emission from direct current glow discharges between a planar cathode and a ring-shaped anode of 0.75 and 1.5 mm diameter, respectively, separated by a gap of 250 μm, was studied in xenon and argon in a pressure range from 75 to 760 Torr. The thickness of the “cathode boundary layer” plasma, in the 100 μm range, and a discharge sustaining voltage of approximately 200 V, indicates that the discharge is restricted to the cathode fall and the negative glow. The radiant excimer emittance at 172 nm increases with pressure and reaches a value of 4 W/cm² for …

Alumina And Synthesis Intermediates Derived From Diethylkaluminum Amide, Benzaldehyde And Water, Stephen E. Hall, Lize Wilcox, William S. Tyree, David A. Lindquist, Malay K. Mazumder

Journal of the Arkansas Academy of Science

The reaction of diethylaluminum amide [Et2AINH2] with benzaldehyde in toluene produces a solution of ethylaluminoxane polymer [EtAlO] and hydrobenzamide [PhCH=NCH(Ph)N=CHPh]. Alumina then is precipitated by the addition of water. Transition aluminas that may be useful in heterogeneous catalyst applications are obtained after calcining. Details of the chemistry of solution intermediates according to 1H NMR and the properties of the alumina product according to surface area analyses and powder x-ray diffraction are described.

Modification Of Surface Properties Of Polymeric Materials, Rajesh Sharma, Robert A. Sims, Malay K. Mazumder

Journal of the Arkansas Academy of Science

Polymeric materials are successfully used in virtually all industries ranging from semiconductors, and coatings, to household appliances, automotive, and biomedical implants. Polymers generally have excellent bulk physical and chemical properties. However, certain properties of polymers such as low surface energy, low wettability, and high electrical resistivity sometimes limit their applications. Changing the bulk formulation of the polymers can alter some of these properties, but in general this is not acceptable as it can affect "desirable" bulk properties. Surface modification techniques have been used to alter polymer surfaces without affecting the bulk properties of the material. Most polymers have very high …

Dendritic Polymers As Bonded Stationary Phases In Capillary Electrochromatography, Chiayu Helen Chao

Seton Hall University Dissertations and Theses (ETDs)

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Insight Into The Selectivity Of Molecular Imprinted Polymers, Thomas Patrick O'Brien

Seton Hall University Dissertations and Theses (ETDs)

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Artificial Neural Networks Used To Predict Electrical Properties Of Polymers, Sanjay K. Mitra, Qing Luo, Jerry A. Darsey

Journal of the Arkansas Academy of Science

The ability to predict properties of molecules prior to their synthesis can be of great importance in optimizing their design. Substantial savings in time as well as cost can be achieved if some desired properties can be predicted prior to the synthesis of the molecule. The outer orbitals of a molecule are primarily responsible for many different properties of the molecules. These outer orbital parameters can be utilized by an intelligent computing system like an Artificial Neural Network to extract necessary knowledge about the properties of the molecule. An Artificial Neural Network was trained to extract electrical parameters of several …

New Studies Of Polyfuran And Polymers Of 3-Substituted Furan Rings, Rose M. Mcconnell, Walter E. Godwin, Bradley Phillips

Journal of the Arkansas Academy of Science

No abstract provided.

Macroporous Polymer Synthesis And Characterization: The Role Of Molecular Recognition In The Regioselectivity Of Sucrose Reactions, Gilbert Joshua Matare

Masters Theses

Molecular recognition has recently emerged as a unique technique for making synthetic polymers with selective binding cavities which can stereoselectively and regioselectively bind to a template molecule in a fashion similar to natural enzymes and antibodies. Its industrial applications in chemistry and biomedicine have been recently exploited. Typical examples include the resolution of amino acids, enantio-separation of racemates and bioactive molecules, selective binding of metal ions and in HPLC investigations. Our research is focused on applying molecular recognition studies to improve the regioselectivity of sucrose reactions.

Sucrose is an abundant industrial raw material of immense industrial importance however, its full …

Tetrabutylammonium Benzoate‐Initiated Polymerization Of Propylene Oxide, Xuemin Chen, Michael R. Van De Mark

Chemistry Faculty Research & Creative Works

The polymerization of propylene oxide by the benzoate anion was aided through the use of the tetrabutylammonium counterion. The effect of the tetrabutylammonium ion was to increase the solubility of the salt and to increase the ion separation. The polymerization was carried out in a pressure reactor at temperatures from 40 to 108°C, producing polymer yields of 2–78%. The study addressed the general effects of solvent, temperature, and ratio of initiator to monomer. © 1993 John Wiley & Sons, Inc. Copyright © 1993 John Wiley & Sons, Inc.

Synthesis Of Organometallic Polymers, Po-Chang Chiang

Masters Theses

By the middle of the nineteenth century, organic chemists found high molecular weight compounds as by-products of some of their experiments. These compounds were thought of as products of a failed reaction. It was not until sixty years ago that the first polymers were deliberately synthesized. Today polymers are used in almost every facet of life and they are becoming more important with each passing day.

This research project focused on synthesizing conducting organometallic polymers. By linking aromatic rings with transition metals, the resultant polymers should have good electrical conductivity because of the interaction of (a) the p electrons on …

Reductive Chemistry Of Dicyanoalkane Reactive Intermediates, Beshakeh Fonkeng

Masters Theses & Specialist Projects

Radical ions are reactive intermediates that are both radicals and ions (either a radical cation or a radical anion). The intrinsic properties of radical ions are not yet well -characterized. Such knowledge is mechanistically important to the organic chemist.

The specific question that motivates this research is as follows: is it possible to controllably express free radical processes in a radical ion independent of ionic chemistry (and vice versa) and, if so, what factors dictate which type of chemistry is expressed?

Our investigation focused on the chemistry of radical anions of dicyanoalkanes that are formed upon metal reduction. Factors influencing …

The Role Of The Voltage Gradient In The Agarose Gel Electrophoresis Of Dna, David Wheeler

Theses and Dissertations in Biomedical Sciences

In Part I of this dissertation, empirical equations for predicting DNA mobility during agarose gel electrophoresis (AGE) from voltage gradient are developed from the data of McDonnel (36) for electrophoresis in a 1.6% agarose gel. These equations represented the data well for DNA between 2 and 10 kilobase pairs (KBp) in length. A computer program, called GELSIM, which incorporates these equations is described in Part II. GELSIM was designed to allow researchers to analyze electrophoresis data by predicting the effect on DNA migration of altering the voltage of electrophoresis. In this way, electrophoretic banding patterns produced using different voltages could …

Study Of Deposition Methods For Silicon Powder, Kamesh V. Gadepally, Kevin B. Tennal, Roger M. Hawk, Al Robles, James A. Gribel

Journal of the Arkansas Academy of Science

Silicon powder tends to agglomerate at normal atmospheric conditions and is, hence, difficult to aerosolize. Several methods of aerosolizing silicon powder and finally depositing it on various substrates were investigated. This paper presents the investigated methods of aerosolization. The electrostatic spray coating used in dry paint application was found to be the most suitable. The general merits of this method and its use for silicon powder deposition to form films are discussed.

Stress-Induced Infrared Frequency Shifts In Polyethylene, George A. Pfeffer, Donald W. Noid

Chemistry Faculty Publications

The molecular dynamics technique is used to study the spectral response of a polyethylene chain in a crystal environment under a mechanical deformation. The MUSIC method, which was previously shown to accurately compute dispersion curves from the time-dependent structure factor, is used. A complete characterization of frequency shifts is presented for various lamellar thickness, temperatures, stress (or pressure), and mass defects.

Computer Simulation Of The Melting Process In Linear Macromolecules, Donald W. Noid, George A. Pfeffer, Stephen Z.D. Cheng, Bernhard Wunderlich

Chemistry Faculty Publications

Polymer crystal melting kinetics is simulated by using molecular dynamics. A simplified molecular model of polyethylene crystal melting consisting of one extended chain on a polyethylene-like crystal surface is presented. The simulation data indicate that the end-to-end distance (eed) of radius of gyration (rg) has a simple exponential dependence on time. The rate constants for eed and rg are found to be temperature and molecular length dependent. A more detailed analysis of polymer crystal melting will be described.

Investigation Of The Synthesis And Polymerization Behavior Of Vinyl Benzoate, Selim Mehmet Erhan

Dissertations

The goal of this study is to present a method that gives higher conversions and molecular weights for the polymerization of vinyl benzoate than obtained in previous investigations.

Polyvinyl benzoate has benzene rings attached to the backbone chain, therefore is hard and rigid. This is a characteristic which has a large application area. However previous studies in polymerizing vinyl benzoate with bulk and solution polymerizations reported low yields and troublesome crosslinking, which has limited its application. Emulsion polymerization method has the advantage of giving high polymerization rates together with high molecular weights, and therefore was chosen as the method for …

Gas Permeation Measurements On Small Polymer Specimens, Karen S. Burns

Chemistry & Biochemistry Theses & Dissertations

Mass spectrometry was used to measure oxygen and nitrogen permeabilities while polarography was used to measure oxygen permeabilities for several contact lens materials. Applicable sample holders were designed and fabricated to accommodate curved and flat specimens with surface areas of 0.5 cm² and 1.0 cm² and thicknesses between 0.025 mm and 0.500 mm. A prepared standard was used to calibrate the mass spectrometric analyses.

The oxygen permeability values determined by mass spectrometry were significantly greater than those determined by polarography. This was attributed to the phase boundary phenomena and the limiting oxygen permeance of water inherent in the …

Investigation Of Complex Formation By Oligomers Of Cytosine And Guanosine, Steven Roberts Davis

Chemistry & Biochemistry Theses & Dissertations

Duplex formation between oligo(C:G) _n where n=3 to 4 was shown not to occur under conditions favorable for duplex formation between poly G and poly C. Instead, a stable guano sine self-structure was found to form which a T_m of 50°C for (Gp)₃ and 80°C for (Gp)₄ at strand concentrations of 10^-5M in 1M NaCl. Neither a duplex nor a self-structure formed in the absence of salt.

Oligomers of guanosine and cytosine were obtained by basic hydrolysis and separated according to chain length using DEAE Sephadex column chromatography. Separation of cytosine oligomers with chain lengths …

Studies Of Radiation Effects In Three High Polymers, Heidi Rene-Mitchell Ries

Physics Theses & Dissertations

Three high polymers, Mylar®, Ultem®, and Kapton®, were irradiated to total doses of 1, 5, and 9.5 gigarad using 1-MeV electrons. The glass transition temperatures (T_g) of the materials before and after irradiation were measured using an AC electrical dissipation factor technique. From the T_g data, it was found that the electron radiation at these total doses results in net chain scissioning in Mylar and net crosslinking in Ultem, while self-mending is predominant in Kapton. The dielectric constant was measured before and after irradiation, but no significant changes due to irradiation were observed. Electron paramagnetic resonance (EPR) …

Interaction Of Calcium With Hema/Maa Copolymers., Michael R. Van De Mark, N. D. Lian, M. Brandon, E. C. Eckstein

Chemistry Faculty Research & Creative Works

Polymeric materials based upon 2-hydroxyethyl methacrylate (HEMA) have been extensively used, especially in biomedical applications. Several reports have appeared in the literature during the past 20 years regarding the behavior of these materials upon exposure to body fluids. The results of these studies have ranged from good biocompatibility to calcification. The presence of methacrylic acid (MAA), in HEMA-based copolymers gives rise to a swelling transition at pH 7. The present study relates the swollen volume of HEMA/MAA gels to the concentrations of calcium salts at a pH where the MAA is ionized, as would occur for implanted gels. This swollen …

Excluded-Volume Effect On Quasi-Elastic Light Scattering By Flexible Macromolecules, Genzo Tanaka, Walter H. Stockmayer

Dartmouth Scholarship

First-order perturbation expressions are developed for the first cumulant (initial time derivative) of the dynamic structure factor observable by photon-correlation measurements of the light scattered by flexible chain molecules in solution. A dimensionless coefficient C, which measures the initial departure of the first cumulant from proportionality to the square of the scattering vector, is found to be only slightly altered by excluded-volume effects.