Thermally conductive and anti-corrosive epoxy composite coatings by synchronously incorporating boron nitride/graphene fillers and polyvinyl pyrrolidone

With the development of modern science and technology, the coatings with the single function of anti-corrosion have failed to cover the special requirements in various practical applications. Particularly, the good heat dissipation effect of anti-corrosive coatings is highly demanded in some devices like electrical machinery, heat exchanger and printed circuit board. Here, a facile, eco-friendly, low-cost method is developed to fabricate thermally conductive and anti-corrosive composite coatings by mixing fillers (including boron nitride (BN) and graphene nanoplatelet (GNP)), polyvinyl pyrrolidone (PVP) and waterborne epoxy resin (WER). The hybridization of BN and GNP is used to provide more barriers to delay the penetration of corrosive medium and construct a denser heat conduction network in the composite coatings. PVP is selected as the compatibilizer to further improve the anti-corrosion and thermal conductivity of composite coatings. The effects of filler types and contents on the anti-corrosive and thermally conductive properties are researched. At the loading of 30 wt% BN and 0.5 wt% GNP, the BN@GNP/PVP/WER coating reaches the optimizing anti-corrosive ability, where the |Z| value holds around 6.5 × 109 Ω cm2 after soaking in the corrosive medium for 7 days, and the Icorr and Ecorr values are 1.9 × 10−9 A/cm2 and -0.62742 V, respectively. Meanwhile, this coating displays great heat conduction with the thermal conductivity of 0.87 W/mK at about 30 wt% filler loading. Moreover, the electrical properties and hydrophilicity of coatings at different filler formulations are studied. It is worth noting that the higher electrical conductivity of the coatings at higher GNP content may accelerate the corrosion rate. This study provides a simple route for the design and manufacture of highly anti-corrosive and heat-conducting composite coatings, which exhibits great potential application in next-generation electronic packaging and devices.