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Thesis (Ph. D.)--University OF MICHIGAN.

The post-polymerization functionalization, characterization and application of block copolymers, hydrogels and cross-linked polymeric micro-beads to particular pharmaceutical and environmental applications are the focus of this thesis. The synthesis of a new amphiphilic and cationic block copolymer, polystyrene- b-poly(N,N,N-trimethylammoniumethylene acrylamide chloride) (PS- b-PTMEACl), from polystyrene-b-poly(tert-butylacrylate) (PS-b-P(tBuA)) is presented. The morphology of the self-assembled copolymers in water is assessed, and finally, we evaluate the potential of this nanoscale system as a bile acid sequestrant. Bile salts represent the major elimination route for cholesterol from the body and bile salt sequestrants have an established reputation as highly effective agents in the facilitation of this elimination. / We also present the functionalization of a series of carbomers and their favorable bile salt binding properties. The synthetic methods were adapted from the post-polymerization functionalization of PS-b-PtBuA. / The peculiar insolubility of ammonium tetraphenylborate in water was the fundamental property exploited in the research described in the final Chapter, where rather than ammonium-ion bearing polymers, ammonium-ion binding polymers are presented. Cross-linked PS resins were functionalized to contain pendent tetraphenylborate moieties and the ammonium-ion sequestering properties of this novel material were investigated. (Organo)ammonium ions from chemical and agro-industrial sources represent a major environmental hazard and our efforts contribute to the elimination of these toxins from effluent.

Polystyrene (PS), functionalized with various ionic groups, was blended with polyamides (PA) in order to investigate the effect of ion-dipole interactions on the miscibility of PS/PA blends. Sulfonic acid groups interact strongly with amides, but catalyze the hydrolysis of the amide bonds of the PA. The neutralization of the sulfonic acid groups eliminates this reaction in the blends, and when the counterion is lithium, strong miscibility enhancement is seen between the lithium sulfonated polystyrene (LiSPS) and polyamides-6 (PA-6), $-$66, $-$610 and $-$11. This miscibility enhancement increases with the lithium sulfonate content of the LiSPS and the amide content of the PA, and is also dependent on the blend composition. An equilibrium thermodynamic approach is used to describe the miscibility behavior of the LiSPS blends with PA-6. When the ionic group is sodium sulfonate, lithium carboxylate or sodium carboxylate, the miscibility enhancement is negligible. As a possibly better alternative to the PS ionomers as a blend component with PAs, novel sulfonated poly(styrene-ethylene-butylene)random ionomers were synthesised and characterized.

We have used the living ring-opening metathesis polymerization (ROMP) reaction with C12(PCy3)2Ru=CHPh to generate a new class of conjugated polymer precursors containing the reactive group 1,2-dichlorocarbonate in their backbone. These polymers possess narrow molecular weight distributions and are easily processable. We have incorporated the 1,2-dichlorocarbonate monomers into block copolymers and have shown that these systems can self-assemble in selective solvents to generate spherical micellar aggregates, as observed by transmission electron microscopy (TEM). Mild hydrolytic treatment of these precursor polymers converts them into novel low band-gap conjugated polymers and block copolymers containing 1,2-diol groups in their backbone. We then report the first synthesis of a ROMP monomer containing the luminescent Ru(phen)32+ moiety. We describe the synthesis, X-Ray structure, electrochemical and photophysical characterization of this novel monomer. Preliminary ROMP studies showed that an oligomeric product is obtained. This oligomer has photophysical and luminescent properties similar to those of the monomer, indicating that the Ru(phen)32+ moiety remained intact during the polymerization. This can potentially lead to the generation of a new class of Ru(phen)32+—containing conjugated polymers. We then used this highly efficient polymerization technique to generate DNAmimetic polymers and copolymers. Polymers with narrow molecular weight distributions and controlled architectures were generated by living ROMP of exo-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboximide. The dicarboximide units have been previously shown to exhibit biological activity, can selectively bind to the nucleic acid base adenine by hydrogen-bonding, and are readily functionalizable. Block copolymers containing these moieties were generated, and underwent self-assembly into nanoscale spherical aggregates, with surface localized molecular recognition motifs. In chapter five, we report the f