Synthesis of thermally stable and low band gap poly(azomethine-urethane)s containing fluorene unit in the backbone

New poly(azomethine-urethane)s (PAMU)s were prepared to investigate the effects of different four diisocyanates on some physical properties such as thermal stability, optical and electrochemical properties. First, the fluorene Schiff base was synthesized as in the literature. Then, this Schiff base was converted to poly(azomethine-urethane)s using diisocyanates (2,4-toluenediisocyanate, 1,4-phenylene diisocyanate, methylene-di-p-phenyl-diisocyanate, and hexamethylene-diisocyanate) via condensation reaction. Second, the structures of PAMUs were confirmed by FT-IR, NMR, and UV-Vis spectral analyses. Cyclic voltammetry (CV) was used to determine the electrochemical oxidationreduction characteristics of (PAMU)s. The CV results of PAMUs compounds showed to have an electrochemical band gap below such as 2.0 eV. The PAMUs were characterized by TGA, DSC, SEM, SEC and AFM techniques. TGA analysis results of compounds showed considerable increasing of the thermal stability of polymers, because of finding of azomethine bond in the main chain.