Synergistic Effects of 1-Octyl-3-Methylimidazolium Hexafluorophosphate and Cellulose Nanocrystals on Improving Polyacrylate Waterborne Anti-Corrosion Coatings

Abstract

In this study, three copolymers of poly(methyl methacrylate) and poly(butyl acrylate) (PMMA-co-PBA) latex containing 1-octyl-3 methylimidazolium hexafluorophosphate (C8mimPF6), cellulose nanocrystals (CNCs), and C8mimPF6-CNCs were successfully synthesized through mini emulsion polymerization. These novel composites were each coated on mild steel panels and tested for their anti-corrosion performance by immersion of the coated samples in 3.5 wt% sodium chloride (NaCl) solution over a certain period. The synergistic anti-corrosion effects of the C8mimPF6-CNCs sample led to the highest coating resistance, charge transfer resistance, and corrosion inhibition efficiency and the lowest diffusion coefficient and corrosion rate. The proposed synergistic mechanism revealed that CNCs enhanced the barrier effect of the coating while C8mimPF6 inhibited corrosion when released.