Fluorescence studies of the self- organization phenomena in film state and solutions of some polyurethanes

The fluorescence properties of stilbene- polyurethane were studied by means of trans-cis photo isomerism and fluorescent emission of the stilbene in polycation and compared with urethane-stilbene derivative and with another cationomer with fluorophore introduced via quaternization of the same precursor with urethane- stilbene halide. In the case of pyrenepolyurethane the process of excimer formation between the pyrene molecules attached to the ionic polyurethane was investigated in tetrahydrofuran (THF), dimethylformamide (DMF) and film state. The formation of aggregates or core-shell micelles was sustained by the fluorescence data, which indicated the existence of pyrene units in the ground state of the molecule, giving rise thus to an explanation for the high excimer-to monomer intensity ratio.