Optimizing dielectric, mechanical, and thermal properties of epoxy resin through molecular design for multifunctional performance

Abstract

Epoxy resins are widely used as dielectric materials in electrical and electronic systems. However, the trend of miniaturization of electronic devices and increasing power output of electrical equipment have created new challenges for dielectric materials, necessitating low dielectric constants, high breakdown strength, and high electrical resistivity. This study introduces three molecular modifications to epoxy resin systems using facile synthesis procedures, including modifiers with bulky groups and crosslinking potential to reduce the dielectric constant while enhancing mechanical and thermal reliability, along with deep traps to increase breakdown strength. The modified epoxy resins exhibit significant improvements. Notably, epoxy/amine resin grafted with only 0.5 wt% maleic anhydride demonstrates a 30% decrease in dielectric constant, a 17-fold increase in volume resistivity, an increase in dielectric breakdown strength from 61.5 to 73.4 kV mm⁻¹, and a rise in tensile strength from 69.7 to 75.4 MPa. Other modifiers also show enhancements in dielectric, mechanical, thermal, and water uptake properties. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) are employed to reveal the chemical structure of the modified epoxy resin and the distribution of modifiers. Results confirm successful grafting and exceptional dispersion without agglomeration. This study demonstrates that small amounts of chemical modifiers can significantly enhance epoxy resin performance. The resulting materials can meet the requirements for next-generation dielectric materials while maintaining low production costs.