Epoxy-functionalized Ti3C2 nanosheet for epoxy coatings with prominent anticorrosion performance

The application of MXene in anticorrosion coatings has attracted recent research interest. Limited information exists on the effect of MXene functionalization on anticorrosion performance. In this work, epoxy-functionalized Ti3C2 nanosheets (E-Ti3C2) were prepared by grafting with (3-glycidyloxypropyl) trimethoxysilane and incorporated into solvent-borne epoxy coatings with low mass fractions of 0.3 wt%, 0.5 wt% and 0.7 wt%. The anticorrosion properties of the coatings were investigated by electrochemical impedance spectroscopy and salt spray tests. The highest impedance was achieved for the 0.5 wt% E-Ti3C2 coating, at nearly three orders of magnitude higher than a pure epoxy coating. In contrast, the coating with unmodified Ti3C2 yielded an impedance improvement of approximately one order of magnitude. Salt spray tests manifested the same anticorrosion results. The enhanced anticorrosion improvement by epoxy-functionalization should result from the better dispersibility and chemical bonding between the E-Ti3C2 and matrix. The mechanical properties and adhesion force of the coatings were also evaluated. A better scratch resistance, higher adhesion force and reduced flexibility resulted after E-Ti3C2 incorporation. [Display omitted] •Epoxy functionalization of Ti3C2 is critical for its application in anticorrosion epoxy coatings.•The coating with 0.5 wt% E-Ti3C2, has the best anticorrosion performance as revealed from EIS and salt spray tests.•Epoxy functionalized Ti3C2 nanosheets showed much better anticorrosion improvement than unmodified Ti3C2 ones.•Better scratch resistance and higher adhesion force but deteriorated flexibility was found after incorporation of E-Ti3C2.