Research on the Corrosion Resistance of Waterborne Epoxy Resin Coating Enhanced by Sodium Alginate-Modified Ti3C2Tx

The enhancement of dispersion stability and interfacial compatibility of nanomaterials within aqueous epoxy matrices represents a pivotal strategy for augmenting the protective performance and corrosion resistance of coatings. In this study, Ti3C2Tx Mxene functionalized with sodium alginate (TSA) was obtained by introducing sodium alginate (SA) into Ti3C2Tx Mxene (T) to improve the corrosion resistance of aqueous epoxy coatings (EP). The dispersion stability of TSA in aqueous medium was quantitatively assessed via ζ-potential measurements, revealing a significant enhancement in stability compared to the reference material T. The long-term stability of TSA/EP composite coatings was systematically evaluated via electrochemical impedance spectroscopy (EIS). Notably, the charge transfer resistance (Rc) remained at 5 × 107 Ω·cm2 after a 60-day accelerated aging test, exhibiting exceptional electrochemical durability. Compared with pure EP coating, this value is improved by 2 orders of magnitude. The improvement is attributed to the fact that active −COOH and −OH groups on the surface of SA enhance the interactions between T nanosheets and EP matrix. Specifically, these functional groups form hydrogen bonds or chemical bonds at the interface. Such interfacial bonding mechanisms enhance the compatibility and interfacial adhesion between T and the EP matrix. These conclusions are further supported by manual scratching experiments. The accessibility and greenness of SA provide a simple and environmentally friendly way of thinking for modifying T.