Effect of humidity on thermally stimulated currents in high field-charged low-density polyethylene with and without a mineral filler

An additional humidity-induced TSC peak in LDPE specimens once exposed to humid air for certain times, whether before or after poling, even then kept in 0% RH for 72 h after poling, is found. This peak can be associated with trapped ions in amorphous-crystalline interface. A consideration on change of TSC direction with polarities of bias field in f-LDPE specimens stored in water saturated air for 72 h before poling may suggest the absorbed water molecules act as shallow traps. Whereas it can be mainfest on our experiment that the fillers serve possibly as deep traps.