Electrical breakdown properties of blend polymers with low density polyethylene and polypropylene

In order to improve the breakdown properties of low density polyethylene (LDPE), the electrical properties of blend polymers of LDPE and Polypropylene (random copolymer of propylene and ethylene: R-EP) have been investigated at 30°C, 60°C and 90°C. In the case of LDPE with 0.917 g/cm³ and R-EP with 0.897 g/cm³, the specimen with a higher R-EP content had a higher impulse breakdown strength at 90°C than the specimen with a lower R-EP content, but there was no clear difference at 30°C and 60°C. However, in the case of LDPE with 0.924 g/cm³ and the same R-EP, any improvement was not recognized for both impulse and dc breakdown strength of blend polymers throughout the temperature range from 30°C to 90°C. The increase in impulse breakdown strength may be related with the striated structure of specimen observed with the polarizing microscope