Dresden 2003 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 20: POSTER A

CPP 20.33: Poster

Montag, 24. März 2003, 19:00–21:00, ZEU/250

Charge Deposition and Decay in Commercial Polypropylene Films — •Zhongming Hu and Bernd-J. Jungnickel — DKI Deutsches Kunststoff-Institut, Schlossgartenstrasse 6, 64289 Darmstadt

Charge Deposition and Decay in Commercial Polypropylene Films

Zhongming Hu and Bernd-J. Jungnickel

Commercial solid and cellular polypropylene (PP) films were charged to different voltages by corona charging and tribocharging. The surface potential decay at room temperature and at about 40 % relative humidity was determined by non-contact probing. Upon corona charging, the surface potential decay is found to be slightly faster in solid PP films compared to cellular samples. The current peak of thermally stimulated discharge current (TSDC) spectra for cellular film arises at higher temperature than for the solid sample. Cellular material exhibits consequently more and deeper traps than the compact one and has a greater charge storage stability upon heating. The TSDC current measurements were also performed with films which were corona-charged in advance by different grid voltages. Such, the amount of deposited charges could be controlled where the deeper traps are filled first. The trap depth distribution was then evaluated by thermal cleaning experiments. The trap depths were found to be around 1 eV where those of solid films are smaller than those of cellular ones.