Water-borne melamine-formaldehyde-cured epoxy-acrylate corrosion resistant coatings

摘要

Organic protective coatings are widely used in corrosion control. However, environmental standards establish that the volatile organic compounds either must be removed or controlled at the lowest possible levels. The carcinogenic environmental impact of volatile organic compounds has led to the substitution of solvent-borne coatings by water-borne coating systems. Among recently developed water-borne coatings, epoxy- and acrylic-based coatings have a special significance over other reported water-borne systems. Keeping in mind, the importance of water-borne coatings in the present work, we report the synthesis of water-borne epoxy-acrylate (EpAc) and melamine-formaldehyde (MF) as well as formulation of their anticorrosive coatings. The structural elucidation of MF-cured EpAc was carried out by FTIR, H-1 NMR, and C-13 NMR spectroscopic techniques. The coatings of EpAc-MF were applied on mild steel strips and were evaluated for physicochemical, physicomechanical characterization, and the anticorrosive performance under different environmental conditions. The present coating system EpAc coatings exhibited superior performance as compared to the reported water-borne epoxyacrylate coatings. The presence of metamine-formaldehyde in the resin increases the scratch hardness, impact resistance, alkali resistance, and thermal stability of these coatings. EpAc-MF-1 was found to cure at ambient temperature and exhibit good physicomechanical properties. (C) 2007 Wiley Periodicals, Inc.