Thiosulfate-functionalized polymer

The associative, thermochemical, and photochemical properties of PATE polymer will be described and evidence will be provided supporting the thesis of labile sulfur-sulfur bonds. Photolysis of a model compound and a polymer similar to PATE but lacking thiosulfate functional groups has been conducted to provide supportive evidence for the proposed sulfur-sulfur bond cleavage reactions. Finally, a preliminary investigation of the imaging characteristics of the PATE polymer is presented in order to place the photochemical investigation in perspective. 

In summary, the presumption from thermal curing data is that heating above 165 °C results in sulfur-sulfur bond rupture and weight loss. Since the degradation is not quantitative, the residual thiosulfate functionality renders the "cured" films somewhat water sensitive, resulting in swelling and weakening of the polymer upon exposure to water. 

Photolysis of Hvdroxy-3-faminoethane thiosulfuric add) propyl phenyl ether (AETSAPPEt. AETSAPPE possesses identical functionality to the thiosulfate group in PATE, but being only monofunctional, AETSAPPE is incapable of forming insoluble polymer upon photolysis. As a result, the reaction products should remain soluble in typical organic solvents, making separation and identification of products possible. 

Following a similar strategy, an ingenious mixed resin bed quench and purification strategy was devised for the Dess-Martin periodinane mediated conversion of alcohols to carbonyls. This hypervalent iodine oxidant was viewed as containing an inherent masked carboxylic acid functionality that was revealed at the end of the reaction (Species (11) Scheme 2.30). Therefore purification was easily achieved by treatment of the reaction mixture with a mixed-resin bed containing both a thiosulfate resin and a polymeric base. The thiosulfate polymer was used to reduce excess hypervalent iodine lodine(V) and (III) oxidation states species to 2-iodoben-zoic acid (11), which was in turn scavenged by the polymeric base [51]. 

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