Study of polarization and relaxation phenomena of polyblend films of poly(vinyl chloride) and poly(methyl methacrylate)

Thermally stimulated discharge current (TSDC) studies were carried out on pure poly(methyl methacrylate), poly(vinyl chloride) and polyblends (of various weight ratios, 100:0, 90:10, 80:20 and 70:30) as a function of polarizing fields at constant temperature, to study the polarization and relaxation phenomena in them. For PVC and different blends a peak around 140–180 °C and for PMMA two peaks at around 95 and 165 °C were observed. No regular variation in peak position for PMMA and blends was observed. The various TSDC parameters i.e. activation energy, charge released and relaxation times were calculated. In the blend samples it is suggested that the chains are so entangled that in the total polarization the dipolar contribution is less and the observed polarization seems to be mainly due to the formation of induced dipoles and an increase in free volume and mobility of charge carriers due to a plasticization effect.