Date of Award
Doctor of Philosophy (PhD)
A series of dimethylaluminum complexes (L)AlMe2 (where HL= 2-(2’-ArNH)phenyl-4-R1-oxazoline) bearing chiral, bidentate anilido-oxazolinate ligands have been prepared and characterized. Six of the complexes, in the presence of an alcohol cocatalyst, are shown to be active initiators for the stereoselective ring opening polymerization of rac-lactide in toluene solution and under bulk conditions, yielding polylactides with a range of tacticity from slightly isotactic to moderately heterotactic. The reactivity and selectivity of these catalysts are discussed based on their substituents.
Polycarbonates have attracted considerable recent interest because of their potential biodegradability and sustainability. Two direct routes were developed for the synthesis of polycarbonates and poly(ether carbonate)s from carbon dioxide (CO2) and diols, promoted by either Cs2CO3/dihalide or CeO2/2-cyanopyridine. While benzylic diols lead to predominantly carbonate linkage, aliphatic diols result in the incorporation of methylene or ethylene unit of dihalides. Moreover, the formation of different linkages was impacted by the dihalides used in the reactions.
Bian, Shi, "Ring Opening Polymerization Of Lactide And Synthesis Of Polycarbonates Directly From Carbon Dioxide And Diols" (2017). Theses and Dissertations. 2100.