Outstanding thermally conductive and anticorrosive polymer composite coating via a multifunctional epoxy curing agent zinc dimethacrylate

Highly thermally conductive metallic materials show great promise in thermal management field. Whereas, inherently high susceptibility of metal materials to corrosion medium would shorten service life and affect heat transfer properties of corresponding materials, thus invalidating their applicability to thermal management devices. This study solves this by preparing an epoxy composite coating with integrated high thermal conductivity (TC) and well long-term corrosion protection performance via synthesizing zinc dimethacrylate (ZDMA) as a novel multifunctional epoxy resin curing agent and designing “point-surface” heterostructure of recrystallized ZDMA nanoparticles-modified boron nitride (BN) sheet with both thermally conductive and anticorrosive functions. The findings reveal that the “double bridging effect” provided by ZDMA and well-dispersed filler result in the formation of efficient heat conduction pathways and barrier effect in the coating. The final coating (h-ZBN/Z/EP) exhibits a high TC of 2.55 W/(m·K), which is more than 11 times that of pure epoxy coating and is much higher than the TC reported for other anti-corrosion polymer coatings. Case calculation and finite element simulation show that the coating can maintain well heat transfer performance of the coated metal material compared to pure epoxy coating. Further combined with the corrosion inhibitory effect of Zn2+ ions, the low-frequency impedance of h-ZBN/Z/EP coating is still as high as 1.32 × 1011 ohm·cm2 after immersion in 3.5 wt% NaCl solution for 360 days. This ingenious strategy provides a fascinating and simple method for preparing multifunctional composite coatings used for long-term protection of heat conduction metallic materials.