LIQUID-CRYSTAL FORMATION IN BINARY-SYSTEMS .1. AN INTERPRETATION OF THE PHASE-DIAGRAMS OF THE AZOXYDIANISOLE-SCHIFF BASE SYSTEMS

In order to confirm the presence of a transition at the temperature where the liquid crystal-isotropic liquid transition curve in the nematogen-rich region is met by the other transition curve, five binary systems comprising azoxydianisole (AA) and a Schiff base were examined by means of differential scanning calorimetry. A small but sharp endothermic peak due to a phase change is observable at the expected temperature upon heating, provided that it is well separated from the eutectic temperature. When the above-mentioned curve intersects the solid-liquid transition curve on the Schiff base-rich side, a liquid crystal coexisting with the solid base is transformed into an isotropic liquid coexisting with the same solid at this temperature.