Thesis (M.S.)--University of Michigan, 1942.

Thesis (M.S.)--University of Michigan, 1989.

In a series ofpreIiminary studies of urea-formaldehyde reactions, the influence of the U:F molar ratio, the temperature and the catalyst were investigated. Subsequently, in a more rigorous evaluation of the influence of four variables on urea-formaldehyde resin formation, viz., U:F molar ratio, pH, temperature and reaction time, a set of twenty reactions were performed using a statistical approach. The results indicate that high resin viscosity is best achieved by using a high U:F molar ratio (1:2) and conducting the reaction at 90°C. Several basic components produced in urea-formaldehyde reactions have been synthesised, characterised by NMR spectroscopy, silylated using bis(trimethylsilyl)trifluoroacetamide and analysed by low resolution mass spectrometry. The use oftriazones as cross-linking agents has been investigated, and a series of 5-substituted triazones have been prepared and their mass fragmentation patterns explored using a combination of low and high resolution mass spectrometry. In order to facilitate interpretation of ¹³C NMR data obtained for U-F resins, internal rotation in various urea derivatives was investigated using variable temperature ¹H and ¹³C NMR spectroscopic study. Signal splittings observed below 247 K have been rationalised in terms of various rotameric structures.

Thesis (M.S.)--University of Michigan, 1987.

No description available.

Thesis (M.S.)--University of Michigan, 1981.

Thesis (M.S.)--University of Michigan, 1943.

Thesis (M.S.)--University of Michigan, 1981.

Thesis (doctoral)--Umeå Universitet, 1984. / Includes bibliographical references.

No / First presented at an August 2001 national meeting of the American Chemical Society, material in this book provides a cross-section of current research in the area of chemistry applied to archaeological questions. Examples are given of the use of analytical methods in the study of a variety of archaeological materials, and inferences that can be made based on data patterns are discussed. Emphasis is on nondestructive testing and new developments in determining an object's age and composition.