Synergistically Improved Thermal Properties and Electromagnetic Wave Absorption of Epoxy Resin Matrix Composites Modified by Boron Nitride and Carbonyl Iron

With the miniaturization and high integration of electronic components, the problems of heat dissipation and electromagnetic interference in microelectronic devices are facing severe challenges. In this work, boron nitride (BN) and carbonyl iron (CI) were first treated with the silane coupling agent, and then BN and CI synergistically modified epoxy resin (EP) matrix composites (BN/CI/EP) were prepared by the casting molding method. The structural and morphological characteristics of the prepared samples were analyzed using X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Investigations were carried out on the thermal properties, reflection loss, and dynamic mechanical properties of the BN and CI modified EP composites. The thermal conductivity of BN/CI/EP composites reached 0.72 W m −1 K −1 , representing a 260% increase over pure EP. At 10% weight loss, the thermal decomposition temperature of BN/CI/EP composites reached 348.5°C, which was 8°C higher than that of pure EP. Additionally, the minimum reflection loss of BN/CI/EP composites attained −20.2 dB at 14 GHz, corresponding to a 221% decrease compared with pure EP. This work provides important insights for developing multifunctional composites that integrate thermal management and wave absorption capabilities.