Aramid fiber-reinforced epoxy resin composites (AFRP) are the main components of electrical equipment such as GIS insulated tie rods, but the poor interfacial bonding between aramid fibers (AF) and epoxy resin (EP) results in a degradation of the material's insulating properties. In this paper, iron phthalocyanine (FePc) molecules are introduced on the AF surface, and the pi-pi interaction effect between the metal phthalocyanine rings is used as a driving force to guide the spontaneous assembly of FePc into a three-dimensional microstructure, and the effect of microstructures with different FePc contents on the insulating properties of AFRP interfaces is investigated. Combining a series of test simulation methods such as surface potential attenuation test, electric tree test, interlayer shear test, and molecular dynamics simulation, reveals the enhancement mechanism of the electrical insulation performance of the interface. The results show that FePc at four contents has an enhancement effect on the flashover voltage along the AF and the breakdown voltage at the AFRP interface, with a maximum enhancement of 25.63% for the flashover voltage and 232.23% for the breakdown voltage.Highlights Self-assembled three-dimensional structures on aramid surfaces were constructed via iron phthalocyanine molecules. The effects of self-assembled structures on physicochemical properties are compared. Modifications substantially increase the breakdown voltage and flashover voltage. The mechanism of microstructure on interface breakdown voltage enhancement is revealed. The overall effect of multiple factors on insulation properties is analyzed. Enhanced interface electrical insulation of aramid-reinforced resin composites via iron phthalocyanine self-assembled structures on the surface of aramid. image
