Bulk Modification of Charge Trapping and Conductivity in Linear Low-Density Polyethylene

Antioxidants, neutral phthalocyanine and titanium dioxide were added to "pure" linear low density polyethylene resin, and films were extruded. Charge storage and conduction properties were measured using TSCD and open and short Circuit TSC; and TSPC, respectively. Antioxidants increased negative and positive storage level and reduced conduction activation energies, but had little effect on lifetime. 0.01 wt% of phthalocyanine increased lifetime in the dark (x5) and conduction activation energy. Trapping may take place by the cage-like amine structure. 5 wt% of titanium dioxide increased charge lifetime by a factor of roughly 7. Defect traps were annealed out at low concentrations, and new deep traps were introduced by the titanium dioxide itself at all concentrations. Additive-matrix boundary trapping is another possibility for the latter two additives.