Metal-organic Framework/ Polypropylene films with enhanced High-temperature Breakdown Strength

In this paper, a method to improve the performance of polypropylene (PP) films for metallized film capacitors at high temperature by adding metal organic frameworks (MOFs) is proposed. With the ultra-low filling loading of 0.05wt%, the DC breakdown field strength of the composite film is 550.9kV/mm and 466.3kV/mm at 25 °C and 85 °C, which are 9.4% and 15.6% higher than those of pure PP (503.5kV/mm and 403.3kV/mm), respectively. The experimental results show that the MOF nanoparticles can improve the crystallization behavior of the films and provide deep traps to capture the carriers at high temperature, resulting in the improved performance of the composite thin film. This method presents a new idea to improve the dielectric properties of polypropylene films at high temperature utilizing MOFs.