Functionalization of boron nitride with poly(catechol‑polyamine) and bis(γ‑triethoxysilylpropyl)tetrasulfide for preparing epoxy nanocomposites with enhanced thermal conductivity

Hexagonal boron nitride (hBN) has garnered significant interest as inorganic thermally conductive material in electronic packaging due to its high-efficiency thermal management capability and electrical insulation properties. However, the relatively inert chemical environment of the BN surface hinders phonon transfer at the interface. Additionally, the high content of inorganic components in the matrix leads to the deterioration of the composite’s mechanical properties. In this research, h-BN surface is modified using poly(catechol-polyamine) (PCPA) and bis (γ-triethoxysi-lylpropyl)tetrasulphide (Si69) (denoted as BN-PCPA-Si69). The noncovalent PCPA modification protects the endothermic properties of BN, Si69 provides covalent bonding between thermally conductive fillers and bisphenol A-type epoxy resin (Ep), and the interfacial compatibility between BN and epoxy resin is improved. The heat conductivity of final BN/Ep composite achieved 0.817 W/(m·K) containing 30 wt% BN. Correspondingly, the heat conductivity of the composite (mBN/Ep) achieved 0.881 W/(m·K) containing 30 wt% BN-PCPA-Si69. Compared to pure epoxy resin (0.200 W/(m·K), the thermal conductivity (TC) of the mBN/Ep composite increased by 364% while maintaining good electrical insulation properties. The proposed BN surface functionalization approach has potential applications in fields such as microelectronic packaging, where materials need to balance high thermal conductivity and electrical insulation.