Investigation of mechanisms responsible for observed broad dielectric relaxation and compatibility of polysulfone- polyvinylidenefluoride blends

Short circuit thermally stimulated depolarization current measurement techniques has been employed to investigate the dielectric relaxation behavior of PSF: PVDF blends. The samples taken were blends of composition PSF: PVDF:: 80:20; 85:15; 90:10 and 95:05 percent by weight. Bimetallized samples were polarized at different temperatures 60, 75, 90 and 115 0 C with various fields 100, 150, 200 and 250kVcm -1 . The short circuit TSDC thermograms of the electrets thus obtained were recorded by reheating the sample in short at a linear rate of 3 0 C/min. The thermograms were characterized by a high value of initial current, a low temperature peak around 75-80 0 C and a prominent broad peak in the temperature interval 130 to 160 0 C. The open circuit thermograms were recorded on bimetallized electrets in a similar way by introducing an air gap between collecting electrode and the electrets. The open-circuit thermograms were characterized by a current of positive polarity with a peak in the temperature interval 150-160 0 C.A comparison of short circuit thermograms with the open circuit thermograms revealed that the peaks observed in the TSDC thermograms are caused primarily by motion of excess charges. The two polymers are found to form compatible blend in the studied composition range. IndexTerms – PSF, PVDF, TSDC, GlassTransition Temperature (Tg), Activation Energy ________________________________________________________________________________________________________