Synthesis and properties of polymers from monosubstituted acetylene derivatives bearing ferroelectric liquid crystalline groups

Novel liquid crystalline polyacetylene derivatives were developed as advanced LC conjugated polymers with quick response to an electric field used as external force. In practice, we synthesized ferroelectric LC conjugated polymers by introducing fluorine-containing chiral LC groups into side chains of polyacetylenes. Phase-transition behaviors of these polymers were examined by differential scanning calorimetry and polarizing optical microscopy. Mesophases as well as higher order structures were evaluated with X-ray diffraction measurements. The polymers synthesized showed chiral nematic (N*), twist grain boundary smectic A (TGBA*), and chiral smectic (SmC*) phases in the heating and cooling processes. Observation of the SmC* phase allows us to expect that the polymer should exhibit ferroelectricity.