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