Preparation and performance comparison of low‐dielectric epoxy resins cured by naphthalene‐ and phenyl‐based active esters

Abstract The poor dielectric properties of epoxy resins limit their application in microelectronics, and active ester curing agent is an effective means to enhance the dielectric properties of epoxy resins. However, the phenyl active ester curing resins nowadays have the problem of low mechanical properties. In this work, a novel naphthalene‐based active ester‐cured resveratrol epoxy resin system (REP/NDA) was prepared for the first time. Compared with the phenyl‐active ester‐cured epoxy resin (REP/PDA), the naphthyl‐active ester prepared epoxy resin has obvious advantages in mechanical properties. The experimental results indicated a tensile strength measurement for REP/NDA at 91.9 MPa, the tensile strength of REP/PDA was 65.3 MPa, and the tensile strength of REP/NDA was 141% of that of REP/PDA. The prepared REP/NDA epoxy resin exhibits favorable dielectric properties, evidenced by a dielectric constant of 3.02 at 10 MHz and a dielectric loss of 0.0042, very good thermal stability ( T 5% of 379°C), excellent water absorption (only 0.49% for 7 days from 2 to 8°C) and good dimensional stability (coefficient of thermal expansion below T g of 77 ppm). The first synthesis of naphthalene‐based active ester curing agent offers a reference for creating new low dielectric epoxy resin materials that work out exceptionally.