Fabrication and characterization of structural/dielectric three-phase composite: Continuous basalt fiber reinforced epoxy resin modified with graphene nanoplates

A kind of multifunctional composite with combined dielectric and mechanical properties was prepared using conductive nanofiller to modify continuous fiber-reinforced polymer composite. The three-phase graphene nanoplates/basalt fiber/E-51 epoxy resin (GNPs/BF/E-51) composite was designed as structural/dielectric composite that could perform energy storage process and sustain mechanical loading simultaneously, possessing potential application as dielectric layer in structural capacitors. The effects of GNPs content on morphology, mechanical, dielectric and electrical properties of E-51 epoxy resin and BF/E-51 composite were investigated. Dielectric mechanism was proposed based on interfacial polarization and electron conduction process. Experimental results show that dielectric permittivity, dielectric loss and alternating-current conductivity sharply increase when GNPs loading reaches 1 wt% for GNPs/E-51 and 0.24 wt% for GNPs/BF/E-51, owing to different dispersing state of GNPs in composites. Mechanical properties of GNPs/BF/E-51 composite increase after the addition of GNPs. GNPs/BF/E-51 composite with suitable GNPs content demonstrates outstanding integrative dielectric and mechanical properties.