Effect of core structures and swallow-tailed groups on the mesomorphic properties of chiral liquid crystals derived from (L)-lactic acid

Abstract

A homologous series of chiral swallow-tailed materials, I(p,q,m,n), derived from (L)-lactic acid was synthesized for investigation of the effects of variation of the molecular core structure and the terminal swallow-tailed group on the formation of mesophases. The mesophases and their corresponding transition temperatures were identified by polarizing optical microscopy and differential scanning calorimetry. The results indicate that the variations of the core structure and of the methylene group between the chiral centre and the swallow-tailed group, have a remarkable effect on the appearance of mesophases; change in length of the swallow-tail group has less effect. The spontaneous polarization and dielectric constant in the ferroelectric SmC* phase were also measured.