Abstract

PANTOJA-CASTRO, Mayra A.  and  GONZALEZ-RODRIGUEZ, Horacio. Study by infrared spectroscopy and thermogravimetric analysis of Tannins and Tannic acid. Rev. latinoam. quím [online]. 2011, vol.39, n.3, pp.107-112. ISSN 0370-5943.

Among the compounds in nature useful for people are tannins, which present large molecular complexity and they had have an ancient use as tanning agents, and nowadays some of them are used due their antioxidant properties for protect metals of corrosion. Also elucidation, synthesis and purification represent a great challenge to obtain them. Due this fact researches have tried to copy the synthesis of less complex compounds similar to tannins. From a different point of view, the use of tannins extracted from trees bark, considered in many places as a waste, grant an extra value to the bark. In this work we have studied and analyzed through gel permeation chromatography (GPC), infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA) the average molecular weight, main functional groups and thermal properties of tannins extracted from Schinopsis quebracho colorado. The results of these analyses are compared with those obtained for the commercial grade tannic acid. The comparison allowed to corroborate that is possible to use tannins from the Schinopsis quebracho colorado bark, with functional groups and thermal properties which tend to be similar to the tannic acid.

Keywords : coating; corrosion; Schinopsis quebracho colorado; tannic acid; tannins.

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