Graphene oxide as 2D flexible anti-settling agent for high-performance titanate whisker/cardanol-based epoxy anticorrosion coatings

Abstract

Titanate whiskers/cardanol-based epoxy coatings with ultra-high anticorrosion performance using graphene oxide (GO) as a 2D lightweight anti-settling agent were prepared. The influence of GO on the filler dispersion, sedimentation, corrosion resistance, and mechanical properties of sodium iron titanate whisker/cardanol-based epoxy coatings was studied. FT-IR, TGA, Raman spectroscopy, optical microscopy, and SEM have been used to characterize the chemical ingredients and morphologies of the coatings. It was found that the addition of GO significantly influenced the dispersibility of titanate whiskers in the resin. A small amount of GO (<0.3 wt.%) increased the aggregation of titanate whiskers, resulting in decreased mechanical and anticorrosion properties. Meanwhile, an optimized amount of GO (0.5 wt.%) effectively reduced the aggregation and sedimentation of titanate whiskers. This interesting correlation was explained by the dual functions of resin-thickening and filler-packing of GO. Therefore, bio-based epoxy coatings with significantly enhanced barrier, mechanical, and adhesion properties were prepared. The impedance modulus at 0.01 Hz remained above 1010 Ω·cm2 after immersing in 3.5 wt.% NaCl solution for 300 days. This study constitutes the first report on applying GO as an anti-settling agent for titanate whisker/epoxy coatings, which is crucial for anticorrosion coatings as well as the GO industry.