SYNTHESIS AND CHARACTERIZATION OF FERROELECTRIC LIQUID-CRYSTALLINE POLYSILOXANES AND POLYMETHACRYLATES CONTAINING [(S)-2-METHYL-1-BUTOXY]PHENYL 4-(ALKYLOXY)BIPHENYL-4'-CARBOXYLATE SIDE GROUPS

Abstract

The synthesis of side-chain liquid crystalline polysiloxanes and polymethacrylates containing 4- [(S)-2-methyl-1-butoxy]phenyl 4-hydroxybiphenyl-4'-carboxylate moieties as mesogenic units and aliphatic spacers containing respectively three to eleven methylene units is presented. Differential scanning calorimetry, optical polarizing microscopy, and X-ray diffraction measurements reveal chiral smectic mesomorphism for all polymers. Both polysiloxanes which contain respectively six and eleven methylene units in the spacers exhibit smectic A, chiral smectic C, and smectic B phases. Among the polymethacrylates prepared in this study, the polymethacrylate containing eleven methylene units in its spacers is the only one revealing smectic A and chiral smectic C phases. The results seem to demonstrate that the tendency toward chiral smectic C mesomorphism increases with increasing spacer length, and the thermal stability of the chiral smectic C mesophase is determined by the flexibility of the polymer backbone.