Release of cerium dibutylphosphate corrosion inhibitors from highly filled epoxy coating systems

Jazyk: angličtina
Rok vydání: 2014
Předmět:
Popis: Carcinogenic chromates are phased out as corrosion inhibitors in organic coatings, and are replaced by benign alternatives. Cerium-based compounds are excellent corrosion inhibitors in an aqueous environment. However, whether they are effective as corrosion inhibitor in an organic coating also depends on their interaction with the coating matrix, which should result in a sufficient release of inhibitors over a desired period of time. In this work we report on the leaching of cerium dibutylphosphate, Ce(dbp)3, from an epoxy coating system as a first step toward a fundamental understanding of the leaching behavior. To this end, coating systems containing various levels of inhibitor loading, ranging from 1 up to 50 wt%, were fabricated. These coatings were characterized using Fourier transform spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). Leaching experiments were performed by exposing the coating films to water, while the concentration of dissolved Ce(dbp)3 in this water was monitored in situ using ultraviolet-visible (UV-vis) spectroscopy. The leaching of inhibitors showed a clear dependence on the initial inhibitor loading of the coating system. For highly loaded coatings (>25 wt%) all inhibitors leach out, whereas for a low loading level (
Databáze: OpenAIRE