Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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Department: search.filters.department.Thesis (Master)--İzmir Institute of Technology, ChemistrySubject: search.filters.subject.Epoxy compounds

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  • Master Thesis
    Enantio-Pure Synthesis of Enyne Epoxides and Their Iron-Catalyzed Sn2" Reactions With Grignard Reagents
    (01. Izmir Institute of Technology, 2020) Artok, Levent; Artok, Levent; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    The use of transition-metal catalysts in synthetic chemistry has gained a lot of significance in the last decade, by virtue of their selectivity wheather regio-isomerically, or enantiomerically, or both. Besides their superior selectivity, these reactions have also been considered as atom economic and environmental-friendly. Iron-catalyzed reactions gained undeniable attention in regard to their low toxicity and presence in enzymatic reactions. Thus, use of the iron catalyst in the synthesis of biologically important and intermediary chemicals bear great significance. Allene motifs, which exist in vast number of naturally occuring compounds are important intermediates in synthesis of bio-active materials due to their versatile reactivity and instrict chirality. The first transition metal-mediated sythesis of allenes was accomplished by 1,3-substitution reaction of propargylic acetates with stoichiometric amounts of organocuprates (Rona et al.,1968). Later on, Fürstner and co-workers have established a technique that, allows the use of catalytic amounts of iron complexes for the reaction of Grignard reagents with propargylic oxiranes which yields -allenol compounds with different modes of addition (Fürstner et al., 2003). In addition to significant developments in this field, our group has established iron-promoted reactions of enyne acetates and oxiranes with Grignard reagents, producing functionalized vinyl allene structures. (Taç et al., 2017). In that study, reactions proceeded regioselectively in 1,5-substitution (SN2'') manner yielded vinylallenes in good to high yields. However, stereoselectivity of the method was not sufficiently satisfactory. Nevertheless, we disclose herein that the corresponding iron-catalyzed reactions of enyne oxiranes with an endocyclic alkenyl moiety are highly stereoselective; vinyl allene products could be obtained in high diastereomeric ratios by this method. Moreover, the ability to synthesize oxirane substrates in high enantiomeric purity allowed the production of the desired enantiopure vinyl allenes.
  • Master Thesis
    Characterization and Corrosion Performance of Γ-Glycidoxyropyltrimethoxsilane Modified Epoxy Polymer
    (Izmir Institute of Technology, 2010) Oturaklı, Şafak; Polat, Hürriyet; Polat, Hürriyet; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    Epoxy polymers have been widely used in a protective coating and adhesive due to its strong adhesion, high chemical resistance, and good processing characterisitics. However; epoxy coatings absorbs moisture easily, and the diffusion of absorbed water into the epoxy.steel interface weakens the interfacial adhesion strength between epoxy and steel in corrosive enviroment, due to the presence of hydrophilic hydroxy group in the cured network (epoxy/amine reaction). In this study, commercial epoxy polymer was chemically modified by γ-glycidoxypropyltrimethoxysilane monomer under the catalysis organotin compound via the reaction between hydroxyl group in epoxy polymer and alkoxy group in silanes, aiming to enhance the corrosion performans of epoxy polymer. Commercial epoxy polymer and silane modifed epoxy polymer were characterized by NMR spectroscopy, FTIR spectroscopy, epoxy equivalent weight measurement, contact angle measurement, surface energy measurement, hardness test and MEK double-rub test. The results showed that γ-glycidoxypropyltrimethoxysilane has been successfully grafted to epoxy polymer. Corrosion performance was evaluated by salt spray test acording to ASTM B117. The results showed that the chemically modified epoxy coating perform an improvement in resistance againts the penetration of water in polymeric resin and beter protectiveness on metalic corrosion.