SYNTHESIS, LIQUID CRYSTALLINE PROPERTIES AND THERMAL STABILITY OF 4-(4-ALKYLOXYPHENYLAZO) BENZOIC ACIDS

The paper details the synthesis, liquid crystalline properties and thermal stabilities of some mesogenic groups with the general formula HOOC-C6H4-N=N-C6H4-OCnH2n+1, n = 6 ÷ 10, 18. Their mesomorphic properties were investigated by differential scanning calorimetry and polarized optical microscopy. All the synthesized compounds presented liquid crystalline properties of nematic or smectic type. The thermal stability was established by using thermogravimetric analysis. The synthesized compounds may be further used in the synthesis of new classes of bent core liquid crystals by reaction with different dihydroxy cores.