Photoactive liquid crystalline polyesters based on bisbenzylidene and pyridine moieties

Photoactive main chain liquid crystalline polyesters containing bis(benzylidene)acetone and aromatic heterocyclic pyridine were synthesized by solution polycondensation. Chemical structure of monomers and polymers were confirmed by FT-IR, 1H and 13C NMR spectroscopy. Thermal property was investigated by TGA and DSC. Optical property of polyesters was studied in chloroform solution and in thin film under UV irradiation and exhibited cis–trans-photoisomerization. This behavior was witnessed by solubility, carbonyl group absorption band in FT-IR, optical microscopy as well as DSC analysis through existence of liquid crystallinity after irradiation of polymers.