An Anisotropically High Thermal Conductive Boron Nitride/Epoxy Composite Based on Nacre‐Mimetic 3D Network

TLDR

Polymer‑based thermal interface materials are sought for high thermal conductivity and electrical insulation, yet composites with boron nitride nanosheets remain limited by inadequate 3D conductive networks. The study aims to fabricate a high‑thermal‑conductivity BNNS/epoxy composite by constructing a nacre‑mimetic 3D conductive network within the epoxy matrix. This is achieved through a unique bidirectional freezing technique that builds the nacre‑mimetic 3D network. The resulting composite reaches 6.07 W m⁻¹ K⁻¹ thermal conductivity at 15 vol % BNNS, with outstanding electrical resistivity and thermal stability, offering a promising route for high‑performance polymer‑based TIMs.

Abstract

Abstract Polymer‐based thermal interface materials (TIMs) with excellent thermal conductivity and electrical resistivity are in high demand in the electronics industry. In the past decade, thermally conductive fillers, such as boron nitride nanosheets (BNNS), were usually incorporated into the polymer‐based TIMs to improve their thermal conductivity for efficient heat management. However, the thermal performance of those composites means that they are still far from practical applications, mainly because of poor control over the 3D conductive network. In the present work, a high thermally conductive BNNS/epoxy composite is fabricated by building a nacre‐mimetic 3D conductive network within an epoxy resin matrix, realized by a unique bidirectional freezing technique. The as‐prepared composite exhibits a high thermal conductivity (6.07 W m −1 K −1 ) at 15 vol% BNNS loading, outstanding electrical resistivity, and thermal stability, making it attractive to electronic packaging applications. In addition, this research provides a promising strategy to achieve high thermal conductive polymer‐based TIMs by building efficient 3D conductive networks.