Mesomorphic and polymerization behaviors of 4-(icosa-1,3-diynyl)benzoic acid

We report the mesomorphic property of 4-(icosa-1,3-diynyl)benzoic acid (16,Ph-DA-CO2H) as a new type of liquid-crystalline 4-carboxyphenyl-substituted diacetylene monomer based on the results obtained by differential scanning calorimetric (DSC), wide-angle X-ray diffraction (XRD), and polarized optical microscopic (POM) measurements. The polymerization of 16,Ph-DA-CO2H was also carried out in the isotropic and liquid-crystalline states with or without UV irradiation.