Self-Healing Performance of Cellulose-Based Gel Coating with Highly Loaded Hybrid Inhibitor

Abstract

The self-healing performance of an ethyl-cellulose-based gel coating with different corrosion inhibitors was investigated in this work. Various contents of 11 alkyl imidazoline (IMO-11) were pre-loaded into the gel coating. The EIS results of scratched coatings with inhibitors confirmed the self-healing performance of the coating. As the inhibitor contents increased, the improved self-healing effect was attributed to inhibitor release, while the increased inhibitor content would also affect the film-forming ability and mechanical properties of the composite coating, and lead to the accelerated failure of the coating. Different contents of thiourea and sodium oleate were added to the gel coating with 25% IMO-11. It was hoped that the hybrid inhibitor in the coating would obtain the synergistic effect of different inhibitors during the self-healing progress. The SEM and FT-IR results indicate the hybrid inhibitor was successfully loaded into the gel coating. The EIS and morphology results of scratched coatings confirmed the enhance effect of the synergistic inhibitor on the self-healing performance of the coating. The high content of the hybrid inhibitor could enhance the corrosion protection effect of the intact gel coating. Once the coating is damaged, the fast released inhibitor could extend the corrosion protection time. The synergistic effect difference of thiourea and sodium oleate with IMO-11 did not show much difference in the coating self-healing effect in this work.