Space charge behaviors in low-density polyethylene

The space charge distributions in LDPE( low-density polyethylene) have been measured by PEA (pulsed Electro-Acoustic) method. Two kinds of LDPE were used; LDPE polymerized under a high pressure process and m-LDPE polymerized with metallocene catalyst. The thickness of a sample was about 100 /spl mu/m. The space charge distributions in both LDPE and m-LDPE depended on the materials of electrodes. Positive and negative carriers were easily injected from the semicon electrode. Home space charge near the Al electrode was formed only in m-LDPE. There was not a big difference in the amount of space charge between m-LDPE and LDPE, but the space charge in LDPE was spreading more widely than that in m-LDPE. These space charge behaviors were compared with the conduction current and the differences between LDPE and m-LDPE were discussed.