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.