AC Impedance of Liquid Crystalline Copolyesters in the Solid Phase

This work deals with the effect of composition on the ac impedance of liquid crystalline copolyester of 4-Hydroxybenzoic Acid (HBA) and 2-Hydroxy 6-Naphthoic Acid (HNA) in the solid phase. The results show that the ac conductivity increases with increasing the content of HBA residues. The Cole-Cole plot yields good semi-circles for liquid crystalline copolyesters specimens. The intensity of the observed relaxation in the plot of the imaginary component of the ac impedance versus frequency increases with the content of HNA residues. This was interpreted to be due to a rotational motion of the identical ester linkages.