Structure and thermal behavior of tannins from acacia dealbata bark and their reactivity toward formaldehyde

• JUSTO LISPERGUER ^[1] ; YANINA SARAVIA ^[2] ; EMILIO VERGARA ^[3]
  1. [1] Universidad del Bio-Bio Facultad de Ciencias Departamento de Química
  2. [2] Conicyt-Regional Centro de Investigación de Polímeros Avanzados
  3. [3] Universidad del Bio-Bio Centro de Investigación en Tecnologías de la Construcción

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• Localización: Journal of the Chilean Chemical Society (Boletín de la Sociedad Chilena de Química), ISSN-e 0717-6309, ISSN 0366-1644, Vol. 61, Nº. 4, 2016, págs. 3188-3190
• Idioma: inglés
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  • The objective of this study was to evaluate the tannin extraction potential taken from the bark of Acacia dealbata. This tannins were extracted with water at 90°C. An extraction yield of 17.2% solids with a Stiasny number of 82% was obtained from the bark extract of Acacia dealbata. The structure was studied by Fourier transform infrared spectroscopy (FTIR). The thermal behavior of tannins was studied by DSC and a glass-transition temperature (Tg) of 116,77°C was determined. The thermal stability of tannins was studied by TGA. At 196.91°C the decomposition is 3.7% and the maximum of the weight loss rate (DTG) of the degradation was 257.77°C. The curing with formaldehyde showed an exotherm reaction in the range of 100-120°C, which is similar to tannins of other species.