Thermal Properties of Model Compounds for Liquid Crystalline Polymers Containing α-Cyanostilbene as a Mesogenic Group

Abstract

Liquid crystallinity of the semi-rigid polymers is affected by the flexible chain length, linkage fashion between rigid and flexible chains, and rigid cores, etc. The twin type of model compounds play more important role to demonstrate the thermal properties of the semi-rigid liquid crystalline polymers than the core type of model compounds. We study liquid crystallinity of twin type compounds containing cyanostilbene as mesogen by polarized optical microscopy, differential scanning calorimetry, and X-ray diffraction measurements. Thermal properties of these model compounds changed with flexible chain length, linkage fashion between rigid and flexible chains, and the position of cyano groups in the central group of mesogen.