Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 275-290). Also available via the Internet.

Ionomers are polymers that contain ionic groups in relatively low concentrations along the polymer backbone. These ionic groups, in the presence of oppositely charged ions, form aggregates that lead to novel physical properties of the polymer. React-A-Seal® and Surlyn® are poly(ethylene-co-methacrylic acid) (EMAA) ionomer-based materials and Nucrel® is the EMAA acid copolymer neutralized to produce Surlyn®. React-A-Seal® , Surlyn® , and Nucrel® recover into their original shapes following a high impact puncture at velocities ranging from 300 to 1200 ft/s ("self-healing"). This self-healing process may be of great benefit in space applications where structures are exposed to matter impacts. A thermal IR camera indicated a temperature increase to 98°C for Nucrel® 925, Surlyn® 8940, React-A-Seal® , and Surlyn® 8920 after initial penetration. To understand and generalize the observed phenomena, questions concerning the mechanism of the puncture resealing must be answered. One suggestion is that the elastic character of the melt created by the puncture drives the self-healing. This inference is based on the observed temperature rise of ~3°C above the melting temperature of the samples (~95°C) during the impact. With the expectation of gaining additional insight into the self-healing phenomenon, a thermodynamic and viscoelastic investigation was conducted using primarily DSC and DMA. Surlyn® and React-A-Seal® showed the characteristic order-disorder transition at ~52°C that has been reported in literature. Master curves were constructed from the creep isotherms for the four EMAA samples. An aging study was performed to investigate the irreproducibility and ®tailing effect” observed in the creep data. The aging study indicated that, with increased aging time and temperature, changes in the polyethylene matrix lead to complexities in morphology resulting in changes in the magnitude and shape of the creep curves. As a result of the thermodynamic, viscoelastic, and high-speed impact experiments it has been theorized that self-healing can occur in Nucrel® 925, Surlyn® 8940, React-A-Seal® , and Surlyn® 8920 because of two features, ionic aggregation and complex flow behavior. / Master of Science

The work presented in this dissertation revolves around the incorporation of t-butyl methacrylate into block copolymers utilizing anionic living polymerization techniques. The synthesis of t-butyl methacrylate/n-hexyl methacrylate and t-butyl methacrylate/2-ethylhexyl methacrylate di- and triblock copolymers was done by initiation with 2-methyl-1,1-diphenylpentyllithium in THF at -78°C by established techniques, and predictable molecular weights and narrow molecular weight distributions were obtained. Subsequent selective acid catalyzed hydrolysis of the t-butyl ester followed by neutralization with an appropriate base allowed the formation of block ioncontaining polymers. The synthesis of triblock polymers of t-butyl methacrylate with butadiene and styrene/butadiene systems and their analogous block ionomers was also carried out utilizing difunctional organolithium initiation of the hydrocarbon monomers in cyclohexane. For the polymerization of the tbma, it was found that the addition of large quantities of a polar solvent, such as THF, endcapping with diphenylethylene, and low temperatures (ca. -70 °C) were necessary to avoid side reactions which were theorized to be carbonyl attack by the dienyl- or styryllithium species. It was found that in the all methacrylic systems mentioned, when the t-butyl methacrylate blocks were in the ester form, i.e. not hydrolyzed to the acid or neutralized to the ionomer, the copolymers were phase mixed as evidenced by thermal analysis. Upon derivatization, however, the block polymers became phase separated. Morphological characterization of the block ionomers indicated that the morphology was dependent on both the ionic content and the ionic block length. Well defined, partially anisotropic, morphologies were observed by SAXS and TEM only in polymers that had both high ionic content and relatively large ionic block lengths. Elastomeric behavior was observed in copolymers with triblock architecture, but the materials degraded prior to plastic flow. On the other hand, all of the diene- and styrene/diene-methacrylates exhibited a multiphase morphology in the precursor state. Analogously to the all methacrylic system, the block ionomers were elastomeric, with the rubbery plateau extended ca. 60 °C relative to the non-ionic precursors. Crosslinking of the poly(butadiene) phase occurred at the onset of plastic flow, rendering the ionomers unable to be thermally processed. / The work presented in this dissertation revolves around the incorporation of t-butyl methacrylate into block copolymers utilizing anionic living polymerization techniques. The synthesis of t-butyl methacrylate/n-hexyl methacrylate and t-butyl methacrylate/2-ethylhexyl methacrylate di- and triblock copolymers was done by initiation with 2-methyl-1,1-diphenylpentyllithium in THF at -78°C by established techniques, and predictable molecular weights and narrow molecular weight distributions were obtained. Subsequent selective acid catalyzed hydrolysis of the t-butyl ester followed by neutralization with an appropriate base allowed the formation of block ioncontaining polymers. The synthesis of triblock polymers of t-butyl methacrylate with butadiene and styrene/butadiene systems and their analogous block ionomers was also carried out utilizing difunctional organolithium initiation of the hydrocarbon monomers in cyclohexane. For the polymerization of the tbma, it was found that the addition of large quantities of a polar solvent, such as THF, endcapping with diphenylethylene, and low temperatures (ca. -70 °C) were necessary to avoid side reactions which were theorized to be carbonyl attack by the dienyl- or styryllithium species. It was found that in the all methacrylic systems mentioned, when the t-butyl methacrylate blocks were in the ester form, i.e. not hydrolyzed to the acid or neutralized to the ionomer, the copolymers were phase mixed as evidenced by thermal analysis. Upon derivatization, however, the block polymers became phase separated. Morphological characterization of the block ionomers indicated that the morphology was dependent on both the ionic content and the ionic block length. Well defined, partially anisotropic, morphologies were observed by SAXS and TEM only in polymers that had both high ionic content and relatively large ionic block lengths. Elastomeric behavior was observed in copolymers with triblock architecture, but the materials degraded prior to plastic flow. On the other hand, all of the diene- and styrene/diene-methacrylates exhibited a multiphase morphology in the precursor state. Analogously to the all methacrylic system, the block ionomers were elastomeric, with the rubbery plateau extended ca. 60 °C relative to the non-ionic precursors. Crosslinking of the poly(butadiene) phase occurred at the onset of plastic flow, rendering the ionomers unable to be thermally processed. / Ph. D.

Magnetic particles have attracted increasing attention in fields ranging from separation processes to electromagnetic information storage an medical application. Various approaches for their synthesis have been developed and studied to satisfy the criteria of production. Improvement and optimization of size, stability, and functionality is of vital importance in biological applications. The main aspect of project, initially, was to study the application of aqueous functionalized magnetic nanoparticles coupled with high gradient magnetic separation technique for the removal of trace residue of organic contaminants from drinking water. However, the importance of synthesizing stable ferrofluid for this purpose became clear later and took precedence over the initial objective. Different approaches were adopted, such as the incorporation of poly(ethylene glycol) methacrylate, ethylenediamine, and chitosan, to enhance the stability of magnetic particles. However, these surface modifications had unfavorable effect on the stability of initial particles. In accord with the initial objective of the project, the possibility of utilization of β-cyclodextrin, as organic pollutant entrapment agent, was investigated in preliminary studies conducted on its interaction with a model compound, procaine hydrochloride. The outcomes of these experiments suggest its potential as a biocompatible removal agent for the elimination of organic pollutant in drinking water system, or other applications that require selective separation of organic compounds.

Magnetic particles have attracted increasing attention in fields ranging from separation processes to electromagnetic information storage an medical application. Various approaches for their synthesis have been developed and studied to satisfy the criteria of production. Improvement and optimization of size, stability, and functionality is of vital importance in biological applications. The main aspect of project, initially, was to study the application of aqueous functionalized magnetic nanoparticles coupled with high gradient magnetic separation technique for the removal of trace residue of organic contaminants from drinking water. However, the importance of synthesizing stable ferrofluid for this purpose became clear later and took precedence over the initial objective. Different approaches were adopted, such as the incorporation of poly(ethylene glycol) methacrylate, ethylenediamine, and chitosan, to enhance the stability of magnetic particles. However, these surface modifications had unfavorable effect on the stability of initial particles. In accord with the initial objective of the project, the possibility of utilization of β-cyclodextrin, as organic pollutant entrapment agent, was investigated in preliminary studies conducted on its interaction with a model compound, procaine hydrochloride. The outcomes of these experiments suggest its potential as a biocompatible removal agent for the elimination of organic pollutant in drinking water system, or other applications that require selective separation of organic compounds.

ABSTRACT HYDROGEL FROM TEMPLATE POLYMERIZATION OF METHACRYLIC ACID AND N-VINYLPYRROLIDONE AND POLYETHYLENEOXIDE Yelda, Erdem Department of Polymer Science and Technology Supervisor : Prof. Dr. Teoman Tin&ccedil / er April 2005, 53 pages This theses covers the preparation and the characterization of a rigid hydrogel from N-Vinyl pyrrolidone-methacrylic acid (VP-MAA) monomers and polyethyleneoxide (PEO) polymer. Hydrogels are hydrophillic natured three dimensional networks which can swell in the presence of water. The VP-MAA-PEO hydrogel was obtained by template polymerization which can be defined as a method of polymer synthesis in which specific interactions consists of the preparation of a polymer (daughter polymer) in the presence of a macromolecular compound (template polymer). The hydrogel of VP-MAA-PEO was synthesized by using azobisisobutyronitrile (AIBN) as the initiator, tetrahydrofurane (THF) as the solvent and the temperature of the system was kept constant at 50&ordm / C. Two kinds of VP-MAA-PEO hydrogels were prepared. The only difference between them were their solubilities in water. This difference is due to different crosslinking agent weight percentages of ethylene glycol dimethacrylic (EGDMA) to make the hydrogel water insoluble. The comparison of two hydrogels were carried by swelling behaviors at different pH values and different temperatures. Thermal stability of these two hydrogels were also examined by differential scanning calorimetry (DSC), spectroscopic properties were compared by using FTIR spectrometer and morphological studies were analyzed by using scanning electron microscope (SEM).

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The diploma thesis deals with a detailed study of he esterification reaction between PVAl and acrylic and methacrylic acids. Tha goal is to prepared PVAl-based macromers bearing (meth)acrylic moieties bound to PVAl macromolecular backbone. Attention will be paid especially to equlibrium establishing times and to the influence of reaction mixture composition on the properties of resulting products.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24636号 / 工博第5142号 / 新制||工||1982(附属図書館) / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 大内 誠, 教授 秋吉 一成, 教授 大北 英生 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM