Performance Research of Natural Mica Modified with Zirconium-Based Metal–Organic Frameworks for an Epoxy Resin Anti-Corrosion Coating

Abstract

A new composite material made from mica and a metal–organic framework (MOF) has been developed to improve the anticorrosive capabilities of epoxy resin coatings. The layered mica was loaded with denser and more uniform UIO-66 nanoparticles after modifying the composite with polyethyleneimine (PEI). The composites were used as fillers to prepare epoxy coatings that exhibited long-lasting active (labyrinth effect produced by mica) and passive (pH-sensitive release of corrosion inhibitors) corrosion protection. Settling experiments showed that polyethyleneimine improved the composites’ compatibility in epoxy resin. After being immersed in a 3.5 wt.% NaCl solution for 60 days, the adhesion of PMC–UIO@MBT/EP increases to 9.01 MPa, while the water absorption rate only reaches 2.57%. It indicates that the coating has good barrier properties and stability. After being soaked in a 3.5 wt.% NaCl solution for 60 days at pH = 7, PMC–UIO@MBT/EP exhibits high low-frequency impedance (8.30 × 108 Ω), as demonstrated by the electronic impedance spectrum (EIS). In addition, the coating also exhibited the highest low-frequency impedance after 30 days in 3.5 wt.% NaCl solution at pH = 11.

Two-Dimensional Metal–Organic Frameworks/Epoxy Composite Coatings with Superior O2/H2O Resistance for Anticorrosion Applications

“…Bozorg et al further developed the nanocomposite containing UiO-66-NH 2 and carbon nanotubes as the additive in the epoxy coating for achieving the enhanced anticorrosion performance . Very recently, Zhu et al synthesized the composite composed of UiO-66, mica nanosheets, 2-mercapto­benzothiazole, and polyethylenimine and utilized the resulting material in the epoxy-based anticorrosive coating . In the realm of anticorrosion materials, two-dimensional (2D) materials such as graphene, few-layer graphene, and graphene oxide have been widely utilized as additives because of their 2D structures with high aspect ratios that can provide exceptional gas-barrier properties − and remarkable anticorrosion performances .…”

“…31 Very recently, Zhu et al synthesized the composite composed of UiO-66, mica nanosheets, 2-mercaptobenzothiazole, and polyethylenimine and utilized the resulting material in the epoxy-based anticorrosive coating. 32 In the realm of anticorrosion materials, two-dimensional (2D) materials such as graphene, few-layer graphene, and graphene oxide have been widely utilized as additives because of their 2D structures with high aspect ratios that can provide exceptional gas-barrier properties 33−35 and remarkable anticorrosion performances. 36 We thus reasoned that by incorporating a highly water-stable Zr-MOF with a 2D structure and hydrophobic chemical functionality in its structure as an additive into the epoxy-based anticorrosive coating, the resulting performance should be better than that of the coatings with 3D Zr-MOFs such as UiO-66.…”