Enhanced thermal conductivity and anticorrosion capabilities of epoxy composite coating with quercetin-modified boron nitride

Abstract

Hexagonal boron nitride (h-BN) as an ideal two-dimensional nanofiller is often utilized to enhance the thermal conductivity and anticorrosion in the polymer matrix composites. However, the poor compatibility and dispersibility severely restrict its further application. To address this issue, herein, a novel h-BN (FBN) filler with excellent compatibility and dispersibility performances was prepared using a bio-based quercetin modifier by a non-covalent modification method. Leveraging the good compatibility between quercetin and epoxy resin (EP), FBN exhibits good dispersion in the EP. Results from thermogravimetric analysis (TG), derivative thermogravimetry (DTG), and differential scanning calorimetry (DSC) analyses prove that the addition of FBN not only significantly improves the thermal conductivity but also evidently enhances the thermal stability of the polymer matrix composite. When the mass ratio of micro-FBN to nano-FBN is 2:1, the optimized FBN/EP composite coating can further enhance the thermal conductivity with 2.385 W m⁻¹ K⁻¹. Additionally, electrochemical impedance spectroscopy (EIS) and neutral salt spray (NSS) analyses demonstrate the superior long-term corrosion protection capability of the FBN composite coating, much better than pure EP and h-BN coatings. This is attributable to that the better dispersion and compatibility of FBN in the composite coating further enhances its barrier effect.