Synthesis and characterization of TiO 2 /acrylic acid-co-2-acrylamido-2-methyl propane sulfonic acid nanogel composite and investigation its self-healing performance in the epoxy coatings

In the present study, the surface of titanium dioxide (TiO2) nanoparticles was modified with superabsorbent gel based on acrylic acid (AA) and 2-acrylamido-2-methyl propane sulfonic acid (AMPS) via in-situ polymerization using 3-(triethoxysilyl) propyl methacrylate (MPS) as a silane coupling agent. The synthesized TiO2 nanogel composite was then incorporated into a commercial epoxy resin in different weight percent (1, 2, and 4) to prepare an effective self-healing epoxy coating. The chemical structure and surface morphology of the prepared nanogel composite were evaluated by Fourier transform infrared (FTIR), X-ray diffraction (XRD), and Field Emission Scanning Electron Microscopy (FESEM). Furthermore, to calculate the weight ratio of the inorganic to organic materials, the ash content test was employed. The effectiveness of the TiO2 nanogel composite as the self-healing material in the epoxy resin was assessed in 3.5 wt.% NaCl solution by potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS).