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Full-Text Articles in Physical Sciences and Mathematics
Development Of Boron-Containing Polyimide Materials And Poly(Arylene Ether)S For Radiation Shielding, Brittani May Collins
Development Of Boron-Containing Polyimide Materials And Poly(Arylene Ether)S For Radiation Shielding, Brittani May Collins
Dissertations, Theses, and Masters Projects
No abstract provided.
Synthesis And Fluorescence Studies Of Spirooxazine-Functionalized Poly(Phenylene Vinylene) Prepared Via Gilch Polymerization And Click Chemistry, Kathryn Anne Peth
Synthesis And Fluorescence Studies Of Spirooxazine-Functionalized Poly(Phenylene Vinylene) Prepared Via Gilch Polymerization And Click Chemistry, Kathryn Anne Peth
Dissertations, Theses, and Masters Projects
No abstract provided.
Characterization Of Pa-11 Flexible Liner Aging In The Laboratory And In Field Environments Throughout The World, Arthur Jaeton Mitman Glover
Characterization Of Pa-11 Flexible Liner Aging In The Laboratory And In Field Environments Throughout The World, Arthur Jaeton Mitman Glover
Dissertations, Theses, and Masters Projects
Polyamide-11 (PA11) is a polymer of the Nylon family whose monomer is obtained from the castor bean, a renewable resource. It is widely used in offshore oil and gas production as a non-rigid flexible pipe liner, allowing for oil and gas transport from the wellhead to floating platforms for processing. The degradation of PA11 over time may lead to the pipe's failure, with possibly catastrophic results which include loss of life. Until now, the characterization of the degredative process has been limited to laboratory studies of the effects of water and temperature on the rate and degree of hydrolysis. In …
Multifunctional Polymer Synthesis And Incorporation Of Gadolinium Compounds And Modified Tungsten Nanoparticles For Improvement Of Radiation Shielding For Use In Outer Space, Emily Grace Harbert
Multifunctional Polymer Synthesis And Incorporation Of Gadolinium Compounds And Modified Tungsten Nanoparticles For Improvement Of Radiation Shielding For Use In Outer Space, Emily Grace Harbert
Dissertations, Theses, and Masters Projects
No abstract provided.
The Synthesis And Spectroscopic Study Of A Spirooxazine-Functionalized Poly(Phenylenevinylene), Jordan Thomas Walk
The Synthesis And Spectroscopic Study Of A Spirooxazine-Functionalized Poly(Phenylenevinylene), Jordan Thomas Walk
Dissertations, Theses, and Masters Projects
No abstract provided.
Effects Of Metal-Based Montmorillonite Clay And Zeolite Additives On The Fire Retardance And Smoke Suppression Of Poly(Vinyl Chloride), Alexander George Zestos
Effects Of Metal-Based Montmorillonite Clay And Zeolite Additives On The Fire Retardance And Smoke Suppression Of Poly(Vinyl Chloride), Alexander George Zestos
Dissertations, Theses, and Masters Projects
No abstract provided.
Novel Approaches To The Fabrication Of Highly Conductive Silver Surfaces Well Adhered To Polyimide Substrates, Luke Michael Davis
Novel Approaches To The Fabrication Of Highly Conductive Silver Surfaces Well Adhered To Polyimide Substrates, Luke Michael Davis
Dissertations, Theses, and Masters Projects
No abstract provided.
Boron Carbide Filled Neutron Shielding Textile Polymers, Derrick Anthony Manzlak
Boron Carbide Filled Neutron Shielding Textile Polymers, Derrick Anthony Manzlak
Dissertations, Theses, and Masters Projects
No abstract provided.
Uv Cure Kinetics Of Dimethacrylate Thin And Thick Samples, Yuemei Zhang
Uv Cure Kinetics Of Dimethacrylate Thin And Thick Samples, Yuemei Zhang
Dissertations, Theses, and Masters Projects
UV curing is using UV light as the energy source to induce the polymerization of liquid monomers and oligomers to form a solid polymer. Because UV polymerization is fast and energy-saving and a UV curable system has no VOC (volatile organic compound), this new technology has developed rapidly from thin film applications to thick sample applications. In addition, since the UV cure process can be controlled spatially and temporally, it also has an important application to make gradient materials with locally optimized properties. However, most research on UV cure is based on thin film applications, and the cure kinetics of …
Synthesis And Characterization Of Hydrogen-Rich Polyimide Materials For Radiation Shielding, Sha Yang
Synthesis And Characterization Of Hydrogen-Rich Polyimide Materials For Radiation Shielding, Sha Yang
Dissertations, Theses, and Masters Projects
No abstract provided.
Photochemical Modification Of Polyethylene Terephthalate Surface, Zhengmao Zhu
Photochemical Modification Of Polyethylene Terephthalate Surface, Zhengmao Zhu
Dissertations, Theses, and Masters Projects
The prospect of obtaining desired surface-mediated characteristics while retaining bulk-mediated physical properties and avoiding potential environmental issues with wet chemical technology lends considerable appeal to photochemical approaches to surface modification.;We undertook a combined experimental and computational approach to investigate the effect of deep UV irradiation on the polyethylene terephthalate (PET) surface. its response to 172 nm UV from a xenon examiner lamp in the absence of oxygen was characterized with X-ray Photoelectron Spectroscopy (XPS), Time of Flight/Secondary Ion Mass Spectrometry (ToF/SIMS), transmission infrared spectroscopy (IR), and Atomic Force Microscopy (AFM). The surface chemistry details suggested that the primary photochemical reactions …
A New Approach To The Synthesis Of Pvc Graft Copolymers, Guangde Chen
A New Approach To The Synthesis Of Pvc Graft Copolymers, Guangde Chen
Dissertations, Theses, and Masters Projects
No abstract provided.
Characterization Of Ionic, Dipolar And Molecular Mobility In Polymer Systems, Zhenrong Guo
Characterization Of Ionic, Dipolar And Molecular Mobility In Polymer Systems, Zhenrong Guo
Dissertations, Theses, and Masters Projects
Changes in the ionic and dipolar molecular mobility in a polymer system are the basis for the changes in the dielectric mechanical properties of polymer materials. Frequency Dependent Dielectric Measurements (FDEMS) and Ion Time-of-Flight (ITOF) are two important techniques to investigate ionic and dipolar molecular mobility in polymer systems. The results can be related to the macro- and molecular dielectric, electrical and dynamic properties of polymeric materials. The combination of these two methods provides a full view of electric, dielectric and dynamic behavior for the systems as they undergo chemical and/or physical changes during polymerization crystallization, vitrification, and/or phase separation.;The …
Solid State Nmr Characterization Of Conductive Polyanilines, Yanina Anatolievna Goddard
Solid State Nmr Characterization Of Conductive Polyanilines, Yanina Anatolievna Goddard
Dissertations, Theses, and Masters Projects
Different forms of ring deuterated polyaniline with different conductivity have been characterized by solid state deuteron nuclear magnetic resonance.;Quadrupole echo (QE) spectra of all forms of polyaniline consist of a superposition of lineshapes for nearly rigid aromatic rings and a small fraction of rings which undergo fast 180?? flips. The intensity of the fast flipping component is temperature dependent and different for conductive emeraldine salt (ES) and non-conductive emeraldine base (EB). This is a manifestation of the different structure and morphology of these polymers.;Simultaneous measurements of QE lineshapes and the relaxation time anisotropies allowed an accurate description of motion in …
Binding Studies On Molecularly Imprinted Polymers, Lucy Yue Hu
Binding Studies On Molecularly Imprinted Polymers, Lucy Yue Hu
Dissertations, Theses, and Masters Projects
Molecular imprinting is a rapidly developing technique for preparation of polymeric materials that are capable of molecular recognition for selective separation and chemical identification. to prepare molecularly imprinted polymers (MIPs), a functional monomer and a crosslinker are polymerized in the presence of a template molecule. Then the template is extracted leaving sites which are complementary in both shape and chemical functionality to those of the template. This resin then becomes capable of selectively absorbing the template species. Because of MIPs' stability, predesigned selectivity, and easy preparation, they have been used for separation, sensor, drug development and directed synthesis.;In this study, …
Synthetic And Mechanistic Studies Of Poly(Vinyl Chloride) And Some Other Chlorinated Polymers, Xianlong Ge
Synthetic And Mechanistic Studies Of Poly(Vinyl Chloride) And Some Other Chlorinated Polymers, Xianlong Ge
Dissertations, Theses, and Masters Projects
Unlike vinyl chloride, 1,2-dichloroethylene (DCE) experienced dimerization under free-radical conditions. Chain transfer to DCE by beta-Cl elimination was shown to be the major reason for its nonpolymerization.;During the chlorination of alkyl chlorides with molecular chlorine, the involvement of a bridged intermediate led to the formation of vicinal chlorides as the major products. The yields of geminal chlorides increased significantly in the presence of solvents that form complexes with chlorine atoms, but such solvents also decreased the reactivity of the chlorination. Thus the chlorination of poly(vinyl chloride) (PVC) in the presence of complexing solvents was not a useful method for the …
Mechanistic Studies On Chlorinated Polymeric Systems, Jing Zhang
Mechanistic Studies On Chlorinated Polymeric Systems, Jing Zhang
Dissertations, Theses, and Masters Projects
No abstract provided.
Transport Analysis In Polymeric Liquids And Films: Investigations In Ionic Mobility Isolation Techniques And Permeability Control, Julia D. Warner
Transport Analysis In Polymeric Liquids And Films: Investigations In Ionic Mobility Isolation Techniques And Permeability Control, Julia D. Warner
Dissertations, Theses, and Masters Projects
An in situ measurement technique that isolates the mobility of charge carriers is described and analyzed. The technique allows significant improvement over conductivity measurements to monitor changes in the physical properties and state of a material as it cures. This is essential in systems where Ni, the number of charge carriers, cannot be assumed constant such as during cure of epoxies, urethanes and polyimides.;Currently, there is an assumption made in the literature that the number of charge carriers present in a curing material is constant when conductivity is used as an in situ measurement technique to monitor changes in mobility. …
Preparation And Characterization Of Polyimide/Organoclay Nanocomposites, Donavon Mark Delozier
Preparation And Characterization Of Polyimide/Organoclay Nanocomposites, Donavon Mark Delozier
Dissertations, Theses, and Masters Projects
The purpose of this research was to prepare nanocomposite materials comprised of exfoliated clay particles in a polyimide matrix. Poly(amide acid)/organoclay solutions and polyimide/organoclay films were prepared and the clay dispersion was characterized by visual inspection, XRD, and TEM. Mechanical measurements and certain thermal characterization measurements were also obtained. The research began by attempting to repeat the procedures set forth in the literature. Most of the polyimide/organoclay nanocomposites were being prepared by mixing prepared poly(amide acid) solutions with organoclay solutions. This simple mixing technology was used in the preparation of various polyimide/organoclay hybrid formulations. In-situ polymerization, which involved performing the …
Characterizing And Monitoring Changes In State Of Polymers During Cure And Use -Aging, Andrew Orschel Meyer
Characterizing And Monitoring Changes In State Of Polymers During Cure And Use -Aging, Andrew Orschel Meyer
Dissertations, Theses, and Masters Projects
Multi Angle Laser Light Scattering (MALLS) and Frequency Dependent Electromagnetic Sensing (FDEMS) provide unique characterizations of polymer systems during cure and use-aging. This research illustrates how MALLS is an extremely accurate technique for absolute characterization of macromolecules, giving molecular weight and size information that other widely used and accepted techniques are incapable of measuring. Application of MALLS to monitoring the changing state of a polyamide-11 system in a water aging environment led to the discovery of an equilibrium molecular weight which is the result of two competing reactions, hydrolysis-degradation and a newly discovered recombination-polymerization reaction. The discovery of this recombination …
Solid State Nmr Characterization Of Structural And Motional Parameter Distributions In Polyamidoammonium Dendrimers, Dariya Ivanovna Malyarenko
Solid State Nmr Characterization Of Structural And Motional Parameter Distributions In Polyamidoammonium Dendrimers, Dariya Ivanovna Malyarenko
Dissertations, Theses, and Masters Projects
The characterization of narrow distributions of structural and motional parameters, and their evolution during the broad glass transition, is performed for deuterated PAMAM dendrimer salts using solid state NMR. The broadening of deuteron quadrupole echo (QE) lineshapes is consistent with the presence of narrow hydrogen bond length distribution (sigmar < 0.25 A) at the spacer amide and branching tertiary amine sites. The temperature dependent averaging of the experimental lineshapes is explained on the basis of fast planar librations in the dendrimer interior, and fast rotation and intermediate regime libration (in an asymmetric cone) of the dendrimer termini. The amplitudes of libration are temperature dependent and higher for low generation dendrimers, while librational rates show Arrhenius behavior only within the glass transition region. In this region, the width of log-normal distribution of rates increases with temperature at sites associated with chlorine counterions. The largest distributions are still less than one order of magnitude wide, unlike the dendrimer in solution or the linear polymers. Interpenetrated low generations (G < 3), uniform intermediate generations (G = 3--5) with surface network, and backfolded high generations (G > 5), are distinguished by interior and termini dynamics.;In the regime of fast motion QE lineshapes are highly sensitive to the presence of narrow structural and motional parameter distributions, and provide constraints on motional geometry independent of rates. The precise characterization of narrow log-normal rate distributions in the intermediate regime can be …
Preparation And Characterization Of Molecular Imprinting Polymer With (S)-Naproxen, Yue Hu
Preparation And Characterization Of Molecular Imprinting Polymer With (S)-Naproxen, Yue Hu
Dissertations, Theses, and Masters Projects
No abstract provided.
In-Situ Frequency-Dependent Electromagnetic Sensing For Monitoring Physical And Chemical Attributes During Chemical Processing, Jeffrey David Rogozinski
In-Situ Frequency-Dependent Electromagnetic Sensing For Monitoring Physical And Chemical Attributes During Chemical Processing, Jeffrey David Rogozinski
Dissertations, Theses, and Masters Projects
The objective of this research was to develop an in-situ sensing technique that monitors the molecular-level response of ions and dipoles to an applied electric field in order to characterize the changes in state of a polymer resin during chemical processing. This technique needs to be capable of monitoring the reaction progress not only in the laboratory setting but also in-situ in the processing tool or reaction environment. Frequency Dependent Electromagnetic Sensing (FDEMS) was selected for this task.;This dissertation investigates the applicability of FDEMS to monitoring two types of processing methods: reactive and batch reactor. The reactive processing system examined …
A Study Of The Aging Of Polyamide-11 Based On Molecular Weight Measurements, Yao Lin
A Study Of The Aging Of Polyamide-11 Based On Molecular Weight Measurements, Yao Lin
Dissertations, Theses, and Masters Projects
No abstract provided.
The Dehydrochlorination Mechanism Of The Internal Allylic Chloride Structure In Poly(Vinyl Chloride), Lynda B. Payne
The Dehydrochlorination Mechanism Of The Internal Allylic Chloride Structure In Poly(Vinyl Chloride), Lynda B. Payne
Dissertations, Theses, and Masters Projects
No abstract provided.
Fabrications And Characterizations Of Boron Containing Polyimides For Radiation Shielding, Christopher Scott Pugh
Fabrications And Characterizations Of Boron Containing Polyimides For Radiation Shielding, Christopher Scott Pugh
Dissertations, Theses, and Masters Projects
No abstract provided.
Additives For Increased Atomic Oxygen Resistance In Cyanate Ester Resins, Sandeep Amar Saggar
Additives For Increased Atomic Oxygen Resistance In Cyanate Ester Resins, Sandeep Amar Saggar
Dissertations, Theses, and Masters Projects
No abstract provided.
Chemical Interaction Of "Declorane Plus" With Antimony Trioxide In Nylon 66, Yum Min Kang
Chemical Interaction Of "Declorane Plus" With Antimony Trioxide In Nylon 66, Yum Min Kang
Dissertations, Theses, and Masters Projects
No abstract provided.
Correlation Of Dynamic Dielectric Properties To Reaction Kinetics And Changing Mechanical Properties Of Epoxy Resins During Cure, Yunfei Wang
Dissertations, Theses, and Masters Projects
The principal objective of this paper is to describe how complex impedance, obtained from frequency dependent dielectric sensing technique, can be used as an effective diagnostic tool for in situ real-time investigation in the fabrication of thermoset structures.;Two epoxy systems (Pr500 from 3M and My720 from Ciba Geigy) with different functionality are characterized in terms of their dielectric, thermal, and rheological behavior. It is observed that there is a one to one relationship between Tg and conversion which is independent of cure temperature. The chemical kinetics of the reaction is satisfactorily described by an autocatalyzed reaction mechanism. The chemical rate …
The Promotion Of Poly(Methyl Methacrylate) Depolymerization By Metal-Based Initiators, Jason Andrew Macko
The Promotion Of Poly(Methyl Methacrylate) Depolymerization By Metal-Based Initiators, Jason Andrew Macko
Dissertations, Theses, and Masters Projects
No abstract provided.