No abstract

The aim of this research is to study the affecting factors on the dielectric strength of polymeric blend [of Epoxy resin and unsaturated polyester] and its composites. A Nano composites were prepared based on polymeric blend ( 80% Ep + 20% UPE), supported by Nano Piezoelectric powder (PZT), of crystalline size (1-10 nm) with weight percentages (2, 4 and 6 Wt%). Dielectric strength (E br ) for the blend and composite samples was studied before and after immersion in water for 11 weeks. The results showed that (E br ) decreases with average the rise of voltage decreasing, increasing the thickness of samples and by form nonlinearly (35.13 kv/s -19.38 kV/s), and with the number of cycles While (E br ) increases with increasing the addition of ratio (36.77 kV/s -43.82 kV/s ). On the other hand, immersing the samples in the water caused a clear reduction of the dielectric strength for each of the blend and composites.