Plasma Deposition of Polymeric Thin Films on Organic Corrosion-Inhibiting Paint Pigments: A Novel Method to Achieve Slow Release

Slow release of corrosion-inhibitive paint pigments is a great challenge to the paint industry, because of the urgent need to replace chromate-containing pigments. Unfortunately, most effective corrosion inhibitors are too soluble for use in paints. In this paper, we present a novel method to modify selected water-soluble organic inhibitor particles to achieve the purpose of slow release. A plasma polymerization technique was used to deposit an ultrathin polymer film on the surface of the inhibitor particles. Infrared spectroscopy (FTIR), time-of-flight secondary ion mass spectroscopy (TOFSIMS), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDX), transmission electron microscopy (TEM), and contact angle data confirmed the successful deposition of the polymer thin film on the inhibitor particles. Using immersion tests and electrochemical techniques, we have demonstrated that the encapsulated water-soluble inhibitor can slowly release into the environment to protect a metal as needed. This technique is a feasible and promising method to promote the replacement of chromate pigments in paints.