Thermal Properties of Liquid Crystals Having an ω-Acryloxyoxyalkyl Group at the Lateral Position

Abstract

Some homologous members of 4-cyanophenyl and 4-alkoxyphenyl 4-(4-alkoxy-2-(ω-acryloyloxy-alkoxy)benzoyloxy)benzoates, and 4-cyanophenyl and 4-alkoxyphenyl 4-alkoxy-2-(ω-acryloyloxy-alkoxy)benzoates have been synthesized, and the thermal and dielectric properties have been investigated. Most members show a nematic phase while these have the bulky substituent at the lateral position. Even in two-ring compounds liquid crystalline phases are formed when both terminal alkoxy groups are suitably long. These compounds easily form glassy states corresponding to the liquid crystalline phases and the isotropic solution, where the relaxation process accompanies a remarkable change in the base line of the DSC thermogram. The thermal and dielectric properties are discussed in terms of the conformational and electrostatic properties of the ω-acryloyloxyalkoxy group.

Key Words:

• liquid crystals
• mesomorphic properties
• lateral substituent
• dielectric properties
• glassy transformation