Structural investigation of conducting polythiophene composites

Abstract

Abstract Polythiophene (PTh) – polyvinyl acetate (PVAc) composite films were prepared by chemical oxidative polymerization with ZnCl2 as oxidant, in methanol solvent at room temperature. In this study DC conductivity as a function of temperature was measured. An attempt has been made to investigate the effect of temperature and concentration of ZnCl2 oxidant on the conductivity of polythiophene and polyvinyl acetate composite films. For fixed wt% of PVAc, the DC electrical conductivity initially increases with the molar concentration of ZnCl2 which increases the rate of polymerization and then decreases with further increase in concentration of ZnCl2 due to reduced segmental motion of the polymer. The Fourier transforms infrared (FTIR) spectra reveal that the structure remains the same throughout the series. The small shift in the observed peak frequencies is due to composition change of ZnCl2, but the overall trend of the IR spectra is the same. From the finger print region it is observed that the terminal branching is completely absent. The ionic transference number is calculated from the polarization current versus time plot. Ionic contribution is found to be dominant. The thermo gravimetry (TG) curves of the samples show single step degradation.