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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Strategic Monomer Design for Alternating Copolymers and Sequence-Specific Properties / 配列特有の性質を示す交互配列ポリマーに向けた戦略的モノマー設計

Kametani, Yuki 23 March 2021 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第23226号 / 工博第4870号 / 新制||工||1760(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 田中 一生 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
2

An investigation into the synthesis of poly(co-maleic anhydride/iso-butyl vinyl ether)with RAFT polymerisation.

Lea, Santa Cinzia, Chemical Sciences & Engineering, Faculty of Engineering, UNSW January 2006 (has links)
Poly (co iso-butyl vinyl ether-alt-maleic anhydride), an alternating copolymer, was synthesised. For this class of copolymers the formation of an electron-donor complex is invoked to explain their microstructure in which the two comonomers strictly alternate. Due to its polarity, this copolymer constitutes a potential additive for imparting hydrophilic properties to a hydrophobic matrix. In order to obtain narrow molecular weight polymers and study the relation between the molecular weight of this additive and its ability to migrate to the host polymer surface, chain transfer agents were introduced in the system and also the Reversible Addition-Fragmentation chain Transfer (RAFT) process was employed. Free radical polymerisation was first carried out to allow for a comparison with the RAFT process and kinetics of copolymerisation was studied by NIR-FTIR and 1H NMR spectroscopy in order to analyse the rate of reaction of each comonomer. Dibenzyl trithiobenzoate, 3-benzyl sulfanyl thiocarbonyl sulfanyl-propionic acid and dibenzyl trithiobenzoate were used as RAFT agents. Results demonstrate that only benzyl dithiobenzoate is able to control the molecular weight of this copolymer and decrease its polydispersity index; possible reasons laying behind this result are discussed. It was also found that, in particular in the presence of benzyl dithiobenzoate, poly(iso-butyl vinyl ether) forms. This is an unusual phenomenon considering that the free radical polymerisation affords alternating copolymers and that iso-butyl vinyl ether is a monomer that polymerises through the cationic process. Experiments were carried out in various solvents in an attempt to counteract this side reaction, but no appreciable correlation between the properties of the solvents and the formation of homopolymer were found. Various hypothesis are considered, however it is likely that, in the conditions adopted, the presence of the RAFT agents alters the equilibrium constant of complex formation favouring the synthesis of the homopolymer. In addition to this side???reaction also inhibition of the copolymerisation reaction was at times encountered and an investigation into this phenomenon was also conducted.
3

An investigation into the synthesis of poly(co-maleic anhydride/iso-butyl vinyl ether)with RAFT polymerisation.

Lea, Santa Cinzia, Chemical Sciences & Engineering, Faculty of Engineering, UNSW January 2006 (has links)
Poly (co iso-butyl vinyl ether-alt-maleic anhydride), an alternating copolymer, was synthesised. For this class of copolymers the formation of an electron-donor complex is invoked to explain their microstructure in which the two comonomers strictly alternate. Due to its polarity, this copolymer constitutes a potential additive for imparting hydrophilic properties to a hydrophobic matrix. In order to obtain narrow molecular weight polymers and study the relation between the molecular weight of this additive and its ability to migrate to the host polymer surface, chain transfer agents were introduced in the system and also the Reversible Addition-Fragmentation chain Transfer (RAFT) process was employed. Free radical polymerisation was first carried out to allow for a comparison with the RAFT process and kinetics of copolymerisation was studied by NIR-FTIR and 1H NMR spectroscopy in order to analyse the rate of reaction of each comonomer. Dibenzyl trithiobenzoate, 3-benzyl sulfanyl thiocarbonyl sulfanyl-propionic acid and dibenzyl trithiobenzoate were used as RAFT agents. Results demonstrate that only benzyl dithiobenzoate is able to control the molecular weight of this copolymer and decrease its polydispersity index; possible reasons laying behind this result are discussed. It was also found that, in particular in the presence of benzyl dithiobenzoate, poly(iso-butyl vinyl ether) forms. This is an unusual phenomenon considering that the free radical polymerisation affords alternating copolymers and that iso-butyl vinyl ether is a monomer that polymerises through the cationic process. Experiments were carried out in various solvents in an attempt to counteract this side reaction, but no appreciable correlation between the properties of the solvents and the formation of homopolymer were found. Various hypothesis are considered, however it is likely that, in the conditions adopted, the presence of the RAFT agents alters the equilibrium constant of complex formation favouring the synthesis of the homopolymer. In addition to this side???reaction also inhibition of the copolymerisation reaction was at times encountered and an investigation into this phenomenon was also conducted.
4

Molecular Design for Precise Sequence Control and Functions of Alternating Copolymers / 交互共重合体の配列精密制御と機能創出に向けた分子設計

Nishimori, Kana 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22470号 / 工博第4731号 / 新制||工||1739(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 竹中 幹人 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
5

LIQUID-CORE CAPSULES VIA INTERFACIAL POLYMERIZATION AND ALTERNATING COPOLYMERIZATION

WU, DAN 03 July 2007 (has links)
No description available.
6

Synthesis and Characterization of Nanoporous Copolymers with Potential Gas Storage Applications

Zhou, Xu 10 October 2013 (has links)
Nanoporous organic polymers, including hypercrosslinked polymers (HCPs), covalent organic frameworks (COFs), polymers of intrinsic microporosity (PIMs), and conjugated microporous polymers (CMPs) etc., are considered good candidates for potential gas storage and gas separation applications. Porosities and surface areas of a series of semirigid alternating copolymers, which contained tert-butyl carboxylate-functionalized stilbene or tert-butyl carboxylate-functionalized styrene, and maleic anhydride or tert-butyl carboxylate-functionalized phenyl maleimide, were investigated using nitrogen sorption/desorption isotherms at 77 K and molecular simulations. These alternating copolymers were found to have Brunauer-Emmett-Teller (BET) surface areas in the range of 20-40 m2/g. Surface areas of these alternating copolymers increased as the steric crowding of the polymer backbone increased, which was the result of introducing extra phenyl rings and/or N-phenyl substituent maleimide units. Surface areas were found to increase as the persistence length increased. A series of HCPs containing functionalized stilbene and N-substituted phenyl maleimide were synthesized via free radical suspension polymerization. The incorporation of these functionalized, chain stiffening, Tg enhancing comonomers raised the Tgs of precursor polymers before they were crosslinked. Surface areas of these HCPs, obtained from nitrogen adsorption/desorption isotherms at 77 K, were up to 1058 m2/g. However, the surface areas of these HCPs were systematically lower than the controls. The high rigidity of the polymer backbone, which was the result of incorporating Tg enhancing comonomer, likely affected the chain mobility of the precursor polymer, decreased the efficiency of post-crosslinking reactions, and thus resulted in lower surface areas. Amine-functionalized styrene/stilbene polymers were prepared via free radical polymerization or post-modification. Amine-containing silica-based sorbents were prepared using the impregnation method. Sorption of CO2 by these materials was tested using TGA and compared with control samples. Both high amine content and certain levels of surface area were found to be important for a sorbent to achieve high CO2 uptake. Highest CO2 uptake (12 wt%) under our testing condition in these materials was achieved by an amine-containing silica sorbent. / Ph. D.

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