Electrical conductivity behaviour of pure and polyblends samples of polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA)

Electrical conductivity of pure PVC, PMMA and their polyblends samples has been studied in detail as a function of polarizing fields at constant temperatures. Different plots were drawn to investigate the nature of mechanism responsible for conduction. The nature of all the thermograms is nonlinear but similar for all temperatures. The plots have two slopes, i.e., ohmic conduction with slope of curve ≈1 at lower voltage region and a non-ohmic conduction with slope ≈1.9 at higher voltage region are observed. The increase in the conductivity and decrease in the activation energy, suggest that plasticization effect is taking place between the polymers when they are blended. Fowler-Nordheim plots are not consistent and showing negative and positive slopes simultaneously for lower as well as higher values of applied voltage. Theoretical and experimental values of βSR and βPF were calculated and the βexp of pure and polyblend samples is in agreement with theoretically βPF. The βexp value lies close to βPF, this shows that Poole-Frenkel mechanism is also effective. The calculated metal electrode potential barrier at a constant voltage suggests that the dominant charge carrier mechanism is Schottky-Richardson type. Hence in the present case both SR and PF mechanisms are seem to be operative.