Synthesis and Properties of Ferroelectric Liquid Crystalline Polythiophene Derivatives with Fhtorine-Containing Chiral Liquid Crystalline Side Chains

Abstract

Ferroelectric liquid crystalline (FLC) substituent with fluorinated asymmetric moiety were introduced into the 3-position of thiophene ring. The polymerization of 2, 5 - dibrominated thiophene monomers were carried out through dehalogenative polycondensation. Poly (3-FLC substituted thiophene) derivatives were fusible and soluble in ordinary organic solvents. Number-average molecular weights of the polymers were 1.2×10^4 . UV-Vis absorption band were observed from 400 to 415 nm. Phase transition behaviors of the polymers and monomers were examined by differential scanning calorimetry (DSC), polarizing optical microscope (POM) and X-ray diffraction (XRD). One of the polymers showed chiral smecfic C phase in the heating and cooling processes. It was found that the main chain conjugation were enhanced by spontaneous orientation of the FLC side chains.