Color stability and corrosion resistivity of natural dye coating paint film consisting of curcumin

The present work aims to study the color stability and the corrosion resistivity of a natural dye coating film. The yellowish dye consisting of curcumin, was extracted from turmeric root (Curcuma longa) by using absolute ethanol as solvent. Blended polymer of Poly(methyl methacrylate) (PMMA) and industrialized acrylic polyol along with xylene as solvent was used as the coating binder. The mixture of the dye and blended polymer was applied on substrate as coating film and left to dry. The coating film was exposed to light consisting of ultraviolet-A (UV-A) to observe the color stability. The color stability of the coating film was observed by using Commission international de I�eclairage (CIE) L*a*b* color coordinates system. The combination of each of the color components L*, a* and b* of the coating film shows the increment in color differences (?E) with time. Electrochemical Impedance Spectroscopy (EIS) was used to record the resistance of the coating films upon the penetration of electrolyte from salt water. The test showed that the resistivity of the coating film decreases as the time of exposure increases. � 2017 American Scientific Publishers All rights reserved.