Synthesis and characterization of halogen-containing ferroelectric liquid crystals and side chain liquid crystalline polymers

A new series of ferroelectric liquid crystals and side chain liquid crystal line polymers based on halogen-containing chiral centres has been synthesiz ed. Chemical structures were analysed by NMR. Liquid crystal phases were ch aracterized by differential scanning calorimetry, optical polarizing micros copy, and X-ray diffractometry. The behaviour of the liquid crystalline pha ses was investigated as a function of spacer units and differing terminal a symmetric moieties. It was found that phase transition temperatures decreas ed with increasing length of the oligooxyethylene spacer unit. Differing te rminal asymmetric moieties led to differing mesophase phenomena. Furthermor e, a wide temperature range (including room temperature) of a chiral smecti c C phase was achieved.