The synthesis of side-chain liquid crystalline polysiloxanes containing either (S)-2-methyl-1-butyl [6-(4-hydroxyphenyl)carbonyloxy]naphthalene-2-carboxylate or (S)-2-methyl-1-butyl 6-[(4-hydroxybiphenyl)-4′-carbonyloxy]naphthalene-2-carboxylate moiety as mesogenic units and aliphatic spacers containing respectively three to eleven methylene units is presented. Differentical scanning calorimetry, optical polarizing microscopy, and X-ray diffraction measurements reveal smectic mesomorphism for all polymers. Most of the obtained polymers display only an enantiotropic smectic A phase. The temperature range of the mesophase formed increases with an increase in the spacer length. All of the synthesized polymers reveal no chiral smectic C phase. The experimental results demonstrate that incorporation of a naphthalene ring in the mesogenic core decreases dramatically the tendency to form a chiral smectic C phase.
- Liquid crystalline polymer
- Naphthalene-based mesogen