Doping C60(OH) to Regulate the Crosslink Network and Energy Band Structures of Epoxy Resin and Allow for Electronic Directional Drive in C60(OH)/EP

The interfacial effect of nanoparticles can effectively regulate electron migration in epoxy composites. In this article, hydroxylated C60 [C60(OH)] was prepared and added to epoxy resin (EP). The inhibition of electron motion in epoxy composites was realized, and the dielectric strength of the epoxy composites was improved. The results of dynamic mechanical analysis (DMA) showed that C60(OH) regulated the structure of the crosslinked EP network and increased the crosslink density by 16.5%. The results of a density functional theory (DFT) simulation showed that the doping of C60(OH) formed a potential energy barrier at the C60(OH)-EP interface, which was conducive to the directional migration and capture of electrons driven to C60(OH). Electrostatic force microscopy (EFM) and pulsed electroacoustic (PEA) experiments showed that C60(OH) had a strong ability to capture charge, and the charge migration rate of C60(OH)/EP was 43% lower than that of pure EP in the presence of 10 kV/mm when the EP was doped with 0.1wt% C60(OH). The breakdown strength and volume resistivity increased by 17.87% and 222%, respectively. Thus, this article provides a new method to improve the dielectric strength of epoxy composites.