Molecular dynamics study on the synergistic effect of HFPT, Cu, and SiC nanoparticles on epoxy resin properties

With the rapid development of ultra-high-voltage (UHV) power systems, epoxy resins (EP) are expected to meet increasingly stringent performance demands. Conventional single-filler strategies have shown limited effectiveness, while multi-filler synergistic approaches offer promising potential. This study explores a hybrid filler system comprising hexafluoropropylene trimer (HFPT), copper (Cu), and silicon carbide (SiC) nanoparticles. Molecular dynamics (MD) simulations are conducted to evaluate the impact of these fillers on key properties of epoxy composites. And a Particle Swarm Optimization Back-Propagation Neural Network Genetic Algorithm (PSO-BPNN-GA) is employed to determine the optimal filler content for enhancing the overall performance of the EP composites. Results reveal that the mean square displacement ( MSD ) decreases then increases with nanoparticle loading, while HFPT tends to raise MSD . The glass transition temperature ( Tg ) increases with total filler content, reaching 168.9 °C, 22.3% higher than that of pure epoxy. Young’s modulus ( E ) also improves, peaking at 4.13 MPa (21.8% increase), with HFPT content having little influence. Thermal conductivity ( TC ) rises with nanoparticle content, up to 0.214 W/m·K (26.6% increase), whereas HFPT content shows little effect. The dielectric constant ( ε ) declines with increasing HFPT, and more notably when Cu content exceeds 2%, reaching a minimum, 2.5. Cohesive energy density electrostatic component ( CEDe ) increases with HFPT and SiC but decreases with Cu. The optimized filler ratio is determined to be HFPT:Cu:SiC = 3.2795:2.8058:1.9441.