Preparation and Thermal Degradation of White Fluorinated Polyimide/TiO2 Composite Films with Strong Shielding Performance

A series of white fluorinated polyimide/TiO2 composite films were prepared by a solution mixing method. They showed high tensile strength beyond 95.1MPa and excellent insulting property with surface and volume resistances exceeding 1.9 × 1011Ω and 2.3 × 1012 Ω cm, respectively, coupled with water absorptions below 1.1%, water contact angles up to 95.9 and whiteness beyond 58.5. It was found that their optical transparency decreased dramatically with the increasing doping of TiO2. The thermal degradation of pure fluorinated polyimide (FPI) and representative polyimide/TiO2 composite film with 5 wt% of TiO2 (PI/TiO2-5 wt%) was also studied.