Waterborne Polyurea Coatings Filled with Sulfonated Graphene Improved Anti-Corrosion Performance

In this paper, an environmentally friendly waterborne polyurea (WPUA) emulsion and its corresponding coating were prepared, which was characterized by dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM). To improve the performance of coating, we doped sulfonated graphene (SG) into WPUA to prepare composite (SG/WPUA). SG can be uniformly dispersed in is stable for a long time (28 days) without delamination. The water resistance with 0.3 wt.% nanofiller improved; contact angle (WCA) result SG/WPUA (89°) > (48.5°), absorption (2.90%) < (9.98%). After immersion treatment, SEM observation revealed that film only generated enlarged microcracks (100 nm) instead holes (150–400 nm, film). Polarization curves electrochemical impedance (EIS) tests show nanosheets low doping content (0.3 wt.%) are more conducive corrosion coatings, model established explain mechanism.