Bifunctional inhibitors of benzotriazole-loaded Ce-MOFs advanced anti-corrosion of epoxy coating

The addition of corrosion inhibitors to epoxy resin coatings is an effective strategy of preventing corrosion process of the substrate. However, the anti-corrosion performance of epoxy resin coatings is not satisfactory in terms of long period of time, owing to the leaking out of corrosion inhibitors. In this paper, we present a composite epoxy resin coating with enhanced long-term anti-corrosion performance, achieved through the synergistic combination of inorganic and organic corrosion inhibitors that refer to metal-organic frameworks (MOFs) with controlled loading of benzotriazole (BTA). The complexation of the inorganic corrosion inhibitor Ce 4+ within the UiO-67 structure (UiO-67-Ce) is accomplished by partially substituting organic ligands with Ce-coordinated 2,2′-bipyridine-5,5′-dicarboxylic acid (Bpydc-Ce). Then, organic corrosion inhibitor BTA is further incorporated into the UiO-67-Ce@BTA by solvent loading process. The organic and inorganic inhibitors-loaded MOFs are dispersed in the epoxy matrix to fabricate anti-corrosion coatings via spraying-coating method. The UiO-67-Ce@BTA/epoxy coating exhibits high corrosion inhibition efficiency (99.95 %), due to efficient release of the bifunctional inhibitors. Additionally, scratch test of the UiO-67-Ce@BTA/epoxy coating demonstrates active corrosion protection performance, which can effectively mitigate localized corrosion. Therefore, we establish an organic-inorganic synergistic anti-corrosion strategy using UiO-67-Ce@BTA as functional nanofillers, offering promising strategy for corrosion protection.