Synthesis and properties of novel thermotropic liquid crystalline copoly(ester-imide)s

Four novel copoly(ester-imide)s based on 3,3′,4,4′-biphenyltetracarboxylic dianhydride, bis(trimellitic acid anhydride) phenyl ester and di-p-aminophenyl ester of dicarboxylic acids were synthesized via two-step method in order to investigate whether two imide mesogenic units with different conformation and polarity could control the formation of LC-phase. Polarizes light microscopy (PLM) and differential scanning calorimetry (DSC) have shown that three polymers formed the nematic phase with “thread schlieren texture” and a polymer formed the nematic phase with “Inversion walls texture”.