Synthesis, Characterization and Curing of Bioinspired Polymers Based on Vinyl Benzyl Thymine and Triethyl Ammonium Chloride

A novel class of environmentally benign, non-toxic and recyclable materials based on vinylbenzyl thymine (VBT) and an ionically-charged vinylbenzyl triethylammonium chloride (VBA) monomers was studied. Several syntheses of VBT VBA copolymers at various comonomer ratio and initiator concentrations were carried out at 65 degrees C using isopropanol as solvent. Samples were taken during the reactions to determine the monomer conversion, chemical composition and molecular weight distribution. The comonomers exhibited similar reactivities and random copolymers with similar chemical compositions were obtained. The curing process involved the irradiation of the copolymer films with a short-wavelength UV light (254nm) for different times, leading to film immobilization on the substrate. The light-induced crosslinking reaction was followed by UV-vis spectroscopy and the immobilization point relative to the gel point was determined. The kinetics of the crosslinking process pointed to a second-order process with respect to the thymine concentration. The experimental results provide complementary information on photo-induced immobilization of VBT VBA films that are crucial for developing new classes of environmentally benign materials and new energy-saving methods.