Influence of the polarizing electrode material on the space charge storage in low density polyethylene

The influence of the polarizing electrode material on the storage of space charge in low density polyethylene (LDPE) was studied using the thermal step technique. Test samples were discs of 1.9 mm thickness provided with different types of electrodes: vacuum deposited gold and aluminium, plasma enhanced chemical vapour deposited silicon carbide (SiC), and pressed aluminium disc electrodes. Space charge was formed using 50 kV de voltage for 72 hours at two different temperatures 25/spl deg/C and 50/spl deg/C. Results indicate that the distribution of space charge density through the sample is dependent on the type of the electrode material, the nature of electrode/polymer interface and temperature of space charge formation.