Polydopamine functionalized Ti3C2 MXene hybrid reinforced waterborne epoxy nanocomposites for enhancing anticorrosion coating application

2D MXene can prevent the penetration of corrosive media and can contribute to the improvement of corrosion resistance performance. However, achieving its uniform dispersion in the polymer matrix is challenging due to its large specific surface area and rapid aggregation. In this study, stable dispersion of polydopamine functionalized Ti3C2 MXene (PDA-TM) hybrid in the waterborne epoxy (WEP) matrix was achieved via in-situ polymerization of the PDA layer on the surface of TM. The Fourier-transform infrared (FTIR) spectrum of PDA-TM showed the blue shift of O-H bond at 3438 cm-1 and the Ti-O bond of TM at 612 cm-1. The characteristic peak of PDA-TM in the XRD pattern appeared at 2θ=3.9° and the PDA bulge became smaller. Both proved the successful synthesis of PDA and TM. The surface wrinkles of the PDA-TM of SEM became more pronounced, and the smooth surface became rougher. This was due to the in-situ polymerization of DA on the surface of TM, which was conducive to avoid tight stacking of TM and expand its interlayer spacing. In addition, The WEP nanocomposite coating showed high impact resistance, strong adhesion, flexibility, and wear resistance. Moreover, PDA-TM decreased the glass transition temperature of WEP from 128.0 to 95.4 °C and improved the reflection loss for electromagnetic wave absorption properties. Furthermore, the |Z|0.01Hz value of the PDA-TM0.5% (6.072 × 105 Ω·cm2) coating was approximately 6 times higher compared to that of the WEP coating after 30-d immersion in 3.5 wt% NaCl solution. The friction coefficient was also a quarter of neat WEP. This indicated that embedding a small amount of PDA functionalized TM nanosheets into WEP coating could improve obviously the corrosion resistance and wear resistance properties. The present research will provide a theoretical basis for the use of TM in the field of anticorrosion and electromagnetic wave absorption.