ABSTRACTThe Mesomorphic behaviors of some ferroelectric liquid crystalline monomers and side-chain polysiloxanes studied by X-ray diffraction Measurement, differential scanning calorimeter and polarizing Microscope. All obtained polymers exhibit wide temperature range of chiral smectic C phase including room temperature.These Mesogenic structures contain oligooxyethylene spacers and (S)-2-Methyl-l -butyl chiral tail via a three phenyl ester linkage (i.e. -Ph-COO-Ph-Ph- or -Ph-Ph-COO-Ph-). Two series of monomers with different biphenyl group linkage position were compared. One shows a novel twisted smectic A phase, in addition to the liquid crystalline sequence (Ch→SA→Sc*) obtained between cholesteric phase and smectic A phase. It also presents an unusual smectic A and chiral smectic C phase.All the prepared polymers present smectic Mesomorphism. As the unit of flexible oligooxyethylene spacers increases, the clearing temperature decreases and the stability of the smectic phase also increases.
Synthesis and Mesomorphic Properties of Novel Bent-shaped Naphthyl Diketones