A new series of four photo-crosslinkable thermotropic liquid crystalline poly(ester amides) were synthesized by direct polycondensation of 2,5-pyridine dicarboxylic acid with two different varying diols and diamines. Two diamines employed in the synthesis were 4,4′-diaminodiphenyl methane and 1,4-diaminobenzene. The arylidene diols 2,5-bis(4-hydroxy-3-methoxybenzylidene)cyclopentanone and 2,6-bis(4-hydroxy-3-methoxybenzylidene)cyclohexanone were also used. The synthesized poly(ester amides) were characterized by qualitative solubility test, FT-IR, 1H and 13C NMR spectra. The monomeric moieties were found to be well incorporated in the polymer back bone. The molecular weight of the polymer was assessed by gel permeation chromatography (GPC). The thermal phase transition behavior and liquid crystallinity of the poly(ester amides) were investigated by differential thermogravimetry (DTG) and hot stage optical polarized microscopy (HOPM), respectively. Interestingly, these poly(ester amides) in dimethylacetamide were found to possess photo-crosslinking characteristics when irradiated by UV light. These polymeric materials may find utility value in optical information storage devices.
Liquid Crystalline and Photoluminescent Properties of Homo- and Copolyesters Composed of 1,3,4-Thiadiazole and Different Lengths of Aliphatic Chains
