## Dissertation Archive

#### Title

Thiosulfate Functional Zwitterions: Synthesis and Characterization of New Thermal or Photo Curable Resins

1986

Dissertation

#### Degree Name

Doctor of Philosophy (PhD)

#### Department

Polymers and High Performance Materials

Shelby F. Thames

New zwitterionic polymers which have free thiosulfate and amine functionalities have been synthesized and structurally characterized. Three synthetic schemes have been employed, (1) formation of a thiosulfate-functional vinyl monomer, vinylbenzyl aminoethane thiosulfuric acid, (2) modification of pre-formed polymers containing either vinylbenzyl chloride or glycidyl acrylate as a co-monomer and (3) reaction of aminoethane thiosulfuric acid with a diepoxide, such as diglycidyl ether of bis-phenol A. While the former two were disappointing in their lack of long-term stability, the latter, poly($\gamma$-(amino $\beta$-thiosulfate) ether) s, were found to be quite stable and water soluble. Investigation of the solution and thermal properties of poly($\gamma$-(amino $\beta$-thiosulfate) ether(s was undertaken. It was found that poly($\gamma$-(amino $\beta$-thiosulfate) ether) s tend to form weakly associated gel-like solutions when sufficiently concentrated above 15% by weight in water. The associations were shown to be less strongly felt with increasing temperature, indicating that the associations are probably electrostatic in nature. The poly($\gamma$-(amino $\beta$-thiosulfate) ether) s were also found to form films which could be insolubilized by heating between 170$\sp\circ$C and 200$\sp\circ$C. Partial loss of thiosulfate functionality was confirmed, implying that crosslinking was by disulfide crosslinks. The poly($\gamma$-(amino $\beta$-thiosulfate) ether) s were also found to self-crosslink by exposure to ultraviolet radiation. It was confirmed by a model compound that the thiosulfate groups are degraded and disulfide bonds result. The quantum yield of this reaction was evaluated for direct photolysis and photolysis with benzophenone, a known triplet sensitizer. The similarity of the quantum yield for the two experiments provides strong evidence that the reaction proceeds, at least in part, through a triplet excited state. Thus, the poly($\gamma$-(amino $\beta$-thiosulfate) ether) s showed significant commercial promise in preliminary evaluation as heat-cure coatings, self-crosslinking emulsifiers and especially as photoresist polymers.