Evaluation of rheological and anticorrosive properties of acrylic paint with tannins

Abstract

The painting system must fulfill the functionality of providing the building with aesthetic value, protection against external agents, mainly humidity and durability over time. Currently there are several types of paints, each with its different properties responsible for the useful life of the building. In this study, copper tannate from the species Schinus terebinthifolius Raddi and Uncaria tomentosa (Willd) were added to commercial acrylic paint. In order to verify the antioxidant activity, the ABTS method was used, which demonstrated that the aqueous extract has better antioxidant activity than tannin. It was found that the copper tannate of both species showed toxicity against Artemia salina, since the LD50 was equal to 1.22 ppm and they are considered toxic according to WHO reference values. According to the results obtained from total solids, it can be noted that there was incorporation of tannin to the paint. The addition of tannin to pure paint caused an increase in shear stress. The results obtained in the corrosion test, it was not possible to confirm the capacity of copper tannate as an anticorrosive coating additive for paints.