Synthesis and characterization of hydrogen bonded liquid crystalline block copolymers based on a Schiff base moiety

Two new series of supramolecular liquid crystalline block copolymers have been synthesized. The first, is based on a backbone that contains carboxylic acid groups. The second is a side chain block copolymer exhibiting hydrogen bonding between the carboxylic acid and the pyridine moiety of a simple low molar mass molecule. These copolymers contain two different flexible spacer lengths, the first fixed at two methylene groups, while the other spacer varies from two to seven groups. The phase behavior and transitional properties of these series have been analyzed by optical polarized microscopy and differential scanning calorimetry, while the structures and properties of the prepared compounds were determined by spectroscopic techniques, elemental analysis, thermogravimetric analysis, and powdered X-ray diffraction.