The effect of resin curing type on the interfacial compatibility between coating and substrate

Graphical abstract Diagram illustrating film formation processes and interfacial compatibility, concluding with graphs depicting corrosion behavior across various frequencies and time points. The image presents a multi-part diagram showcasing processes related to film formation and interfacial compatibility on a substrate. On the left, two sections depict film formation mechanisms (a and b), illustrating resin and curing agent clusters, along with water evaporation leading to film creation. The centre section outlines interfacial compatibility with covalent bonds illustrated by labeled diagrams (with reference numbers 718 and 719) showing coatings like carboxylate salts. On the right, there are graphs labeled (a), (b), and (c) demonstrating corrosion behavior over different frequencies measured in Hertz, plotting logarithmic impedance against frequency with various data points representing time intervals. Each graph includes a fitting line, capturing the data flow left to right and bottom to top. Purpose This paper aims to investigate the comprehensive corrosion resistance of various film-forming and curing types of resins on the surfaces of typical aluminum alloys. Design/methodology/approach The chemical composition and surface morphology of coatings, including 718, 719 and epoxy resins, were analyzed using infrared spectroscopy and laser confocal microscopy. Contact angle measurements were performed to evaluate the wettability of different coatings. Furthermore, the interfacial bonding performance between waterborne resin coatings and aluminum alloy substrates, as well as the spatio-temporal evolution of coating corrosion resistance under NaCl solution immersion, was assessed through electrochemical impedance spectroscopy (EIS) and adhesion testing. Findings Both thermoplastic and thermosetting resins were found to form continuous and complete film layers on the surfaces of aluminum alloys. Under conditions of comparable surface integrity and contact angles, distinct differences in interfacial stability were observed among the various resin systems. These variations in interfacial compatibility between coatings and substrates were characterized using EIS and adhesion tests. Originality/value This study establishes a theoretical foundation for the development of high-performance and durable waterborne anticorrosion coatings.