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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.
41

Terminal 1,1-disubstituted olefins synthesis via nickel catalyzed hydroalkenylation of styrenes with α-olefins.

January 2011 (has links)
He, Lisi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 69-73). / Abstracts in English and Chinese. / Acknowledgement --- p.I / Table of Contents --- p.II / Abstract --- p.III / Abstract (Chinese Version) --- p.IV / Abbreviation --- p.V / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- "Synthesis of Terminal 1,1 -Disubstituted Olefins" --- p.1 / Chapter 1.2 --- Nickel Hydride Reactions with Olefins --- p.5 / Chapter 1.3 --- Objective and Approach --- p.16 / Chapter CHAPTER 2 --- RESULTS AND DISCUSSION --- p.20 / Chapter 2.1 --- Reaction Condition Optimization --- p.20 / Chapter 2.2 --- Substrates Scope Expansion --- p.27 / Chapter 2.3 --- Examples of Post-coupling Modifications --- p.35 / Chapter 2.4 --- Application in a sp2-sp3 Heck-like Reaction --- p.38 / Chapter CHAPTER 3 --- CONCLUSION --- p.43 / APPENDIX EXPERIMENTAL --- p.46 / REFERENCE --- p.69 / GC CHROMATOGRAMS & NMR SPECTRA FOR NEW COMPOUNDS
42

Biocatalytic resolution of substituted styrene oxides / Charl Alan Yeates

Yeates, Charl Alan January 2001 (has links)
Thesis (M.Sc. (Pharmaceutical Chemistry)--Potchefstroom University for Christian Higher Education, 2002.
43

The effect of chain growth retardation in the graft polymerization of styrene onto cellulose acetate

Hamburger, C. Joseph 01 January 1967 (has links)
No description available.
44

Emulsion polymerization of styrene using a reactive surfactant /

Wang, Xiaoru, January 2000 (has links)
Thesis (Ph. D.)--Lehigh University, 2000. / Includes bibliographical references and vita.
45

Rotational molding of acrylonitrile-butadiene-styrene polymers and blends /

Spencer, Mark Grant, January 2003 (has links) (PDF)
Thesis (M.S.)--Brigham Young University. Dept. of Chemical Engineering, 2003. / Includes bibliographical references (p. 69-74).
46

Biocatalytic resolution of substituted styrene oxides / Charl Alan Yeates

Yeates, Charl Alan January 2001 (has links)
Stereochemistry and chirality are arguably two of the most important subjects pertaining to the development of new pharmaceutical drugs. Since enantiomers have the potential to encompass different pharmacological effects in biological systems, both enantiomers have to be tested for pharmacological activity. Not only has obtaining these single enantiomers become crucial, but formulation of the pure enantiomer of a drug also has the potential to contain advantages for both pharmaceutical formulation and therapeutic effect. Epoxide hydrolase is an enzyme commonly found in nature that catalyses the hydrolysis of epoxides, resulting in the formation of the corresponding vicinal diol. Over the last few years a large amount of research has been completed on these enzymes from sources such as mammals, insects, bacteria and fungi. Micro-organisms especially have enjoyed ample attention because of their abundant supply. Recently it was found that certain yeasts contain this enzyme and have the ability to enantioselectively catalyse certain hydrolysis reactions. Styrene oxides are terminal epoxides that are, due to the reactivity of the epoxide ring, useful synthons in the organic synthesis of pharmaceutical products. The first objective of this project was to synthesize three nitro derivatives of styrene oxide namely para-, meta-, and ortho-nitrostyrene oxide. Al three products were obtained from the corresponding nitrophenacyl bromide in yields of 52%, 90% and 57% respectively. The second objective was lo find a suitable yeast slrain containing the epoxide hydrolase enzyme to enantioselectively hydrolyse the synthesised products and unsubstituted styrene oxide. A screening was completed during which 410 yeast strains from more than 44 genera were tested. Epoxide hydrolase activity was found to be widespread throughout the screened yeast domain, while the genera Candida, Debaryomyces, Pichia, Rhodosporidium, Rhodotorula and Trichosporon specifically were very successful in catalysing the hydrolysis of the substrates. Rhodosporidium toruloides UOFS Y-0471 and Rhodotorula glutinis UOFS Y-0653 were chosen for further studies because of their superior enantioselectivity. The final objective was to optimise these reactions in terms of pH, temperature and substrate concentration. It was found that a pH value of 7.2 and a temperature of 45’C yielded optimal enzyme activity. Increased temperatures (45’C), however, lead to a decrease in enantioselectivity and, in the case of R. toruloides together with the substrate puranitrostyrene oxide, reversed enantioselectivity. Lower temperatures (15’C) increased enantioselectivity, resulting in a remarkable improvement from a 10% yield of the single enantiomer (45’C) to a 35% yield. Surprisingly this temperature decrease had a very small affect upon the reaction time. / Thesis (M.Sc. (Pharmaceutical Chemistry)--Potchefstroom University for Christian Higher Education, 2002.
47

Resonance two photon ionization study of binary clusters of styrene with polar molecules /

Mahmoud, Hatem Ahmed, January 2004 (has links)
Thesis (Ph. D.)--Virginia Commonwealth University, 2004. / Prepared for: Dept. of Chemistry. Includes bibliographical references (leaves 143-157). Also available online.
48

Catalytic hydrogenation of alpha-methylstyrene in liquid phase in stirred reactor

Johnson, Douglas Lewellyn, January 1956 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1956. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 184-188).
49

The role of mixed anionic-nonionic systems of surfacants in the emulsion polymerization of stryene /

Colombié, Damien, January 1999 (has links)
Thesis (Ph. D.)--Lehigh University, 1999. / Includes vita. Includes bibliographic references.
50

Manufacturing of metal-free carbon-based catalysts for styrene production / Développement des catalyseurs sans métaux à base de carbone pour la production de styrène

Ba, Housseinou 24 July 2015 (has links)
Le styrène (ST) est l'un des monomères aromatiques insaturés les plus importants dans l'industrie pétrochimique moderne. Le procédé de déshydrogénation (DH) de l'éthylbenzène (EB) en ST, représentant actuellement 90% de la production de ST, nécessite l'utilisation de catalyseurs hautement actifs et stables, et permettant un grand transfert de masse. Dans ce travail, nous avons développé de nouveaux matériaux sans métaux à base de carbone, utilisant les nanodiamants (NDs) comme phase active pour la production de ST. Les NDs ont été déposés sur différents supports 2D et 3D à base de carbure de silicium et de carbone, permettant d'améliorer leur dispersion, et conduisant ainsi à un catalyseur exempt de métal très stable avec des performances en DH élevées. Nous avons également réussi à synthétiser des matériaux carbonés dopés à l'azote (N@C) présentant une activité élevée et stable en DH comparée à celle obtenue sur NDs. Cette phase active N@C a été obtenue à partir de produits alimentaires (le D-glucose, l'acide citrique et le carbonate d'ammonium) par un procédé facile à mettre en œuvre, et peut aussi très bien être déposée sur d'autres supports macroscopiques. / Styrene (ST) is one of the most important unsaturated aromatic monomers in modern petrochemical industry. The catalytic dehydrogenation reaction (DH) of ethylbenzene (EB) into styrene, which accounts for 90% of the ST production, demands highly activated and stabilized catalysts, as well as easily handing and efficient mass diffusion. In this work, we developed novel metal-free carbon-based materials using nanodiamonds (NDs) as an active phase for potential industrial catalysts for the direct dehydrogenation route to produce ST. The NDs were successfully immobilized on different 2D and 3D carbon-based and silicon carbide supports which could help to improve their dispersion, leading to metal-free catalyst with high catalytic performance and stability. We have also succeeded in synthesizing nitrogen-doped carbon materials (N@C) displaying a high and stable dehydrogenation activity for the ST production in place of NDs. These active N@C catalysts were produced from food processing materials, i.e. D-glucose, citric acid and ammonium carbonate, and could be also easily dressed on macroscopic supports by a facile and scalable method.

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