SF6, O2, air glow discharge improve the electret property of biaxially oriented polypropylene film

SF₆ ,O₂, air cold plasma are used for surface modification of the biaxially oriented polypropylene (BOPP) films. The effect of surface grafting on electret property is investigated. Surface potential is characterized as a parameter to evalue charge storage capacity, and half value temperature (T_1/2 ) of thermal stimulated charge decay (TSCD) is an indicator of charge storage stability. The experiment result show that surface grafting increase the charge storage capacity 50% and T_1/2 raise 25°C. IR spectrum gives some detail information about the chemical structure change taking piece during treatment, especially introduction of polar groups C=O,C-F etc. Finally the relationship between chemical component and trap density and modification effect are discussed