Effect of Steric Factor on Mesomorphic Stability, II: Binary Mixtures of Homologues of 4-(4′-Substituted Phenylazo)-1-naphthyl-4″-alkoxybenzoates

Abstract

Sixteen mesomorphic derivatives of the title compounds have been investigated for their phase behavior. These compounds constitute four homologous series that differ from each other by the substituent X. The latter varies between CH₃O, CH₃, Cl, and NO₂, and the number (n) of carbons in the alkoxy chain varies, within a homologous series, between 8, 10, 12, and 14. All possible binary mixtures made from any two homologues were prepared and characterized for their mesophase behavior by differential scanning calorimetry (DSC) and polarized light microscopy (PLM). Phase diagrams for the 24 binary combinations were constructed to investigate the effect of inclusion of the 1,4-naphthalene moiety, as well as the variation in the alkoxy chain length, on the mesomorphic properties in mixed systems.

Keywords:

• steric factor
• binary mixtures
• 4-(4′ -substituted phenylazo)-1-naphthyl-4″ -alkoxybenzoates