Effect of oxidation and space charge on high-field phenomena of low-density polyethylene prepared by metallocene catalyst

We used low-density polyethylene (LDPE) prepared using metallocene catalyst (m-LDPE) and linear-LDPE prepared using Ziegler catalyst (LLDPE). The current density of slightly oxidized m-LDPE and LLDPE films is lower than that of unoxidized ones. The breakdown strength of m-LDPE and LLDPE films decreases with the progress of oxidation. In addition we consider the effect of space charge by the pre-stress method. It is found that m-LDPE has lower current density than LLDPE, but the sum of space charge of m-LDPE is larger than that of LLDPE.