Doping C-60(OH) to Regulate the Crosslink Network and Energy Band Structures of Epoxy Resin and Allow for Electronic Directional Drive in C-60(OH)/EP

The interfacial effect of nanoparticles can effectively regulate electron migration in epoxy composites. In this article, hydroxylated C-60 [C-60(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 C-60(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 C-60(OH) formed a potential energy barrier at the C-60(OH)-EP interface, which was conducive to the directional migration and capture of electrons driven to C-60(OH). Electrostatic force microscopy (EFM) and pulsed electroacoustic (PEA) experiments showed that C-60(OH) had a strong ability to capture charge, and the charge migration rate of C-60(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% C-60(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.