Improved Energy Storage Performance of Biaxially Stretched Polypropylene Films Based on Molecular Semiconductor Grafting

Previous studies have confirmed that the energy storage performances of modified polypropylene (PP) by chemical grafting has been significantly improved. However, as an indispensable link in the production of capacitor films, the biaxial tensile has a significant effect on the micro structures and macro properties of modified PP materials. In this work, the differences in micro structures between direct hot pressed and biaxial stretched PP composites films with micro addition of grafted molecular semiconductors are studied. Based on situ characterization technology in micro regions of polymers developed in the laboratory, the surface potential and trap distribution characteristics of nanoscale regions in pure and composite materials are compared. The energy storage performances of different samples at 25 and 120 ℃ are tested. It is proved that the biaxial stretching process can be applied to PP composites based on molecular semiconductor grafting, and the stretched films still show a remarkable performance improvement, which has a certain practical application prospect in the industry.