High-field electrical properties of new LDPE films prepared using metallocene catalyst

Now low-density polyethylene (M-LDPE) prepared using metallocene catalyst has narrower composition distribution and molecular weight distributions than linear low-density polyethylene (LLDPE) using Ziegler catalyst. The authors compared the electrical insulating properties of M-LDPE films and conventional LLDPE films. The high-field current of M-LDPE was found to be lower than that of LLDPE. The difference in current increased with the decrease of temperature. The high-field current was much reduced in M-LDPE with a low melting point. The impulse breakdown strength of M-LDPE increased with the decrease of temperature. The insulating properties of M-LDPE with a low melting point were improved at 30 °C. These results were explained by the fact that M-LDPE with a low melting point includes more low-molecular-weight components. We also discuss the effects of antioxidant on the electrical properties of M-LDPE. We compared the electrical conduction and breakdown strength of undoped M-LDPE and antioxidant-doped M-LDPE. Differences in their electrical properties were minor. It was found that the excellent properties of M-LDPE do not depend on the effects of antioxidant.