Chemical deacetylation natural xanthan (Jungbunzlauer®)

• Published in: Polímeros, ciência e tecnologia Vol. 21; no. 1; pp. 47 - 52
• Main Authors: Pinto, Ellen P., Furlan, Lígia, Vendruscolo, Claire T.
• Format: Journal Article
• Language: English
• Published: Associação Brasileira de Polímeros 01.01.2011
• Subjects: deacetylation; Natural xanthan; reaction parameters
• ISSN: 0104-1428; 1678-5169
• DOI: 10.1590/S0104-14282011005000005

With the aim of adapting a method for removal of acetyl groups from xanthan, reactions of chemical deacetylation were carried out with natural xanthan (Jungbunzlauer®) with variations on the following parameters: biopolymer and alkali concentration (sodium and potassium hydroxide). The deacetylation reaction was performed at 25 ºC for three hours. The proposed methodology was efficient to promote the deacetylation reaction. The viscosity of xanthan increased when the alkali concentration was higher in the deacetylation reaction. Xanthan concentration in the solution used in the deacetylation reaction did not influence the solutions viscosity, as similar results in both tested biopolymer concentrations (0.5 and 1%) were obtained for all experiments in different shear rates. Deacetylation reactions at 25 ºC for three hours with sodium and potassium hydroxide in 0.01 mol.L-1 showed a viscosity of 410 and 420 mPa.s at 10 s-1 and acetylation degree 1.3 e 1.4%, respectively.