Unveiling the role of substrate properties in shaping film formation in crosslinked waterborne coatings

This study examines the influence of substrate properties on the film formation mechanism of waterborne (WB) anti-corrosive coatings, a sustainable alternative to solvent-based coatings. While the environmental benefits of WB coatings, such as reduced VOC emissions and improved workplace safety, are well recognized, their performance on real-world substrates has been underexplored. This research addresses how substrate characteristics, including roughness, hydrophilicity, and water absorption, affect the water-loss profile during the coating process and, consequently, the film formation behavior and final properties of the cured coating. A combination of gravimetry and Fourier Transform Infrared Spectroscopy (FTIR) was employed to monitor water-loss profiles both independently and comparatively. Cryo-Scanning Electron Microscopy (Cryo-SEM) of forming films captured at distinct stages of water loss (t = 0, end of stage I, II, and III) revealed the morphological evolution of the coating. Furthermore, rheological analyses were performed to assess the drying and curing behavior on different substrates. These findings provide valuable insights into the substrate-dependent behavior of WB coatings, emphasizing their potential and limitations for industrial applications. By understanding the critical role of substrates, this work advances the development of more robust WB anti-corrosive coatings for diverse environmental conditions and substrate types.