Remarkably improved electrical insulating performances of lightweight polypropylene nanocomposites with fullerene

A polypropylene/fullerene nanocomposite was fabricated via solution processing with good dispersion of the fullerene nanoparticles. It was observed that a small amount of fullerene (similar to 1 wt. parts per thousand) can significantly improve the direct current (DC) electrical insulation performance (i.e. improved space charge distribution, greater DC dielectric breakdown strength, and larger DC volume resistivity) of polypropylene. Thermally stimulated depolarization current tests indicate that fullerene doping remarkably increases the deep trap density of pure polypropylene. The mechanisms by which the electrical properties of the polypropylene nanocomposites were improved are the introduction of deep traps and the high electron affinity of fullerene. The deep traps result from the interfaces between polypropylene and fullerene. This work provides a potential method to tailor lightweight nanodielectric materials with excellent electrical insulating performances.