Characterization and Modeling of Environmentally Benign Thymine Polymers

DÉBORA MARTINO; FREDDY GARCÍA; DIANA ESTENOZ; JOHN WARNER

Los Cocos (Argentina)

Simposio; III Simposio Binacional Argentino-Chileno - ARCHIPOL 2005; 2005

The synthesis of “bioinspired” polymers based on styrene containing thymine is studied. These polymers are similar to polystyrene (PS) except that thymine and charged functional groups are chemically bonded to the structure of the PS. These environmentally benign, water-soluble and non-toxic polymers undergo a 2p + 2p photodimerization reaction of the pendant thymine units when exposed to UV radiation (~254 nm). The polymers create crosslinked networks in regions of UV exposure, rendering the polymer insoluble in those areas. VBT was copolymerized in a free radical process with ionically charged monomers such as TEQ or VPS. The final products were analyzed by H1 NMR, elemental analysis, and size exclusion chromatography (SEC). The curing process involves the irradiation with UV. To quantitatively assess the effects of polymer composition and irradiation dose on the photo-dimerization reaction, the UV-vis spectra of toned VBT:VPS polymers were monitored. The batch solution copolymerization process at low temperature was modeled (assuming the standard styrene) in order to predict the evolution of the global variables and the molecular structure of the polymers. A reasonable agreement was observed between the predictions and the experimental data.