Polyimide Composites with Fluorinated Graphene and Functionalized Boron Nitride Nanosheets for Heat Dissipation

AbstractPolyimide (PI) with excellent comprehensive properties has been extensively applied in electronic devices. The miniaturization and integration of electrical equipment put forward more stringent requirements for heat dissipation, so the composite with high thermal conductivity and low dielectric properties has become a critical factor. In this work, fluorinated graphene (FG) and boron nitride nanosheet modified with polydopamine (PDA@BNNS) were filled into the PI matrix as fillers to prepare FG/PDA@BNNS/PI composites. The bridging of FG and BNNS formed the three-dimensional (3D) fillers with hybrid structure, leading to the construction of a thermal conductivity (TC) network inside the composites. The resulting PI composite film with 4.99 wt% FG/PDA@BNNS exhibited excellent comprehensive properties, including ultra-low dielectric constant of 1.65, low loss of 0.013 at 1 MHz and high thermal conductivity of 2.464 Wm-1K-1. In addition, it also showed standout breakdown resistance (81.22 kV/mm) and mechanical properties that the tensile strength reached 86.52 MPa. This report can inspire the future development of composites for electronic packaging.