Benzodifuranone based color-changing epoxy-polyamine coating.

Abstract A new color-changing epoxy coating was developed by incorporating benzodifuranone (1,4-BDF) pigments into epoxy-polyamine coating matrix. The 1,4-BDF based epoxy coating exhibited a color change from dark blue to brown responding to environmental conditions, such as temperature, UV light, and pH. The color of the coating was demonstrated by the spectral reflectance and CIELAB values measured by a spectro-guide spectrophotometer. The color change was due to the reaction of 1,4-BDF pigment with the polyamine curing agent to form an unstable product characterized by UV/Vis and FTIR analysis. Moreover, the coating's opacity and light reflectance changed along with the color change. Opacity is an effective parameter to link the UV accelerated testing and sunlight exposure to demonstrate the change of the coating's appearance. Graphical abstract The color change of the 1,4-BDF based epoxy-polyamine coating under UV exposure. Image 1 Highlights • 1,4-BDF pigment is firstly applied in coatings and leads to a color change. • Environmental conditions trigger a color change of the 1,4-BDF based epoxy coating. • The reasons for the color change are comprehensively investigated and understood. • The hiding power of the pigmented coating also changes along with the color change. [ABSTRACT FROM AUTHOR]