The synthesis and chemistry of some new cyclic diesters were investigated. The first part of the thesis is concerned with the study of new cyclic diesters derived from thiosulfurous acid, namely cyclic dialkoxy disulfides and their structural thionosulfite isomers. The second part focuses on the development of a new methodology for the synthesis of cyclic carbonates (carbonic acid diesters). / The synthesis of new cyclic dialkoxy-disulfides is described in Chapter 3. Five new molecules have been synthesized and fully characterized. An X-ray structure was obtained for the 2,3-furandimethylene dialkoxy disulfide. The substrates were prepared in an attempt to rationalize some of the existing limitations of the synthetic methodology. / The relationship and possible interconversion between the newly prepared cyclic dialkoxy disulfides and their structural thionosulfite isomers were investigated. Benzene dimethanoate disulfide was successfully converted to its structural thionosulfite isomer under acidic conditions. Further investigations show the existence of a reversible sulfur extrusion process between thionosulfite and sulfoxylate. This sequential transformation brings the first chemical demonstration that branched bond sulfur can indeed be involved in sulfur extrusion as was first predicted by Foss in 1950. / Finally, a highly efficient method to convert alkenes and CO2 into cyclic carbonates directly in water is presented in the second part of the thesis. Using N-bromosuccinimide (NBS) together with 1,8-diazabicyclo [5,4,0] undec-7-ene (DBU) in water, alkenes were converted into cyclic carbonates nearly quantitatively. Cyclic carbonates were also formed efficiently by using a catalytic amount of bromide ion together with aqueous hydrogen peroxide.

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1909. / The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed April 22, 2009)

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Surface properties of a number of minerals including talc, graphite and sulphides such as chalcopyrite and galena were investigated. A new method of surface preparation for the layer- type, inherently hydrophobic minerals was developed. A correlation has been shown between contact angle, zeta potential and flotation behaviour. The hydrophilic-to-hydrophobic ratios of various minerals were estimated and their role in this correlation discussed. / Critical surface tensions of wetting ((gamma)(,c)) were determined using pure liquids as well as aqueous solutions. Adsorption densities of methanol ((GAMMA)(,Lv)) and viscosities were used to explain the mechanism of wetting and the frequently observed (gamma)(,c) value of (TURNEQ) 30 mN/m for a number of hydrophobic samples. The adhesion tension diagrams were used to identify the critical surface tension range within which preferential wetting occurs between two inherently hydrophobic minerals. This range has been exploited for the flotation separation of binary mixtures of the minerals. Induction periods estimated as a function of surface tension ((gamma)(,Lv)) have been discussed with reference to the separation tests. The separations employing the methanol solutions have been compared with those obtained using a more conventional system of Lignosol-MIBC solutions. / The effect of sulphur formation and hydrocarbon chain length of the wettability and floatability of sulphides were also determined as a function of (gamma)(,Lv).

No description available.

Thesis (Ph.D.) -- University of Adelaide, Dept. of Economic Geology, 1978. / 2 microfiche in end pocket.

Thesis (B.Sc.(Hons)) --University of Adelaide, Department of Economic Geology,1969.

Thesis (M.S.)--University of Wisconsin--Madison, 1973. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 73-76).

Thesis (M.S.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.