电晕充电多孔PTFE/PP复合驻极体过滤材料的电荷存储特性

Charge storage characteristics in hybrid electret film consisting of porous PTFE and PP with negative corona charging

报道采用电晕充电方法,对用高温熔融粘合工艺制备得到的双向拉伸多孔PTFE与PP复合过滤材料进行驻极体改性,并采用热刺激放电和表面电位测量等方法研究了材料的电荷存储稳定性,根据驻极体相关理论,对实验结果进行了解释.结果表明,电晕充电的多孔PTFE/熔喷或纺粘PP覆膜材料中,既存在空间电荷又存在极化电荷,复合膜的界面是电荷陷阱的主要来源.从不同面对复合膜材料进行充电时,材料具有完全不同的电荷存储特性.由于材料体内空间电荷和极化电荷的极性相反、相互补偿,表面电位测定并不能真正反映材料内部电荷的存储状态.

The charge storage characteristics of hybrid electret film consisting of porous PTFE and PP, which come from Shanghai Dagong New Materials Co. Ltd., are investigated by means of corona charging, open-circuit thermally stimulating discharge （TSD） analysis and isothermal surface-potential measurement. The results indicate that there are space charge and polar charge for the hybrid film charged by means of corona discharge method, and the interface between PP and PTFE layers are the main source of charge traps. When charging is carried out through different sides, the difference of TSD current spectra is very large. The electric field generated by space charge can cause polarization of polymer and give rise compensative charge of space charge, so that the surface potential measurement can＇ t reveal hybrid films. to polar charge, which exists as the charge characteristics inside