Effect of molecular structure on the phase behaviour of some liquid crystalline compounds and their mixtures XII. Binary mixtures of homologues of unsymmetrical 1,4-phenylene bis (4-substituted benzoates)

Abstract

Twentyfour liquid crystalline esters of the type 4-(n-C n H2n+1O)C6H4COOC6H4OOCC6H4-X-4 have been investigated for their phase behaviour. These compounds constitute six homologous series that differ from each other by the substituent X. The latter varies between CH3O, CH3, Cl, CN, NO2, and n-C n H2n+1O, and the number (n) of carbons varies, within a homologous series, between 6, 8, 14, and 16. All possible binary mixtures made from any two homologues were prepared and characterized for their mesophase behaviour by differential scanning calorimetry and polarizing optical microscopy.