ELECTRICAL-CONDUCTION IN BIAXIALLY-ORIENTED POLYPROPYLENE

The electrical conduction in biaxially-oriented polypropylene (BOPP) h as been studied. Space charge limited current (SCLC), Schottky and Poo le-Frenkel effects and ionic conduction processes are discussed. Therm ally stimulated polarization current (TSPC) studies showed a decrease in conductivity from 4.3 x 10(-16) to 3.0 X 10(-17) (ohm cm)-1 at 80-d egrees-C after hexane treatment of BOPP. The decrease can be attribute d to the removal of impurities by hexane treatment. The conduction is extrinsic in nature. Thermally stimulated current investigations show the presence of impurity traps in BOPP. A good fit of the ionic theory to be experimental data of the steady state currents in the temperatu re range 50-100-degrees-C suggests ion conduction to be predominant. B ulk electronic conduction also plays important role at high temperatur es.