NEMATIC LIQUID-CRYSTALS WITH POLAR ORDERING FORMED FROM SIMPLE AROMATIC POLYESTER

In this study, we describe a distinct nematic liquid crystal with pola r ordering which is formed from the polar rod-like aromatic copolyeste r comprising 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid. The polarity in the nematic phase appears along the nematic director as d etermined by second-harmonic generation (SHG). It was found that SHG a ctivity appears in compounds with a high degree of polymerization. Thi s suggests that the strong dipole-dipole interaction between polar rod -like molecules is the origin of the polar structure.