Oxidation of cashew tree gum exudate polysaccharide with TEMPO reagent

Journal of the Brazilian Chemical Society

Pablyana L. R. Cunha¹  Jeanny S. Maciel¹  Maria Rita Sierakowski²  Regina C. M. De Paula¹  Judith P. A. Feitosa¹ 

[1] ,Universidade Federal do Ceará Departamento de Química Orgânica e Inorgânica Fortaleza CE ,Brazil

关键词: cashew gum;    oxidation;    TEMPO;    Anacardium occidentale;    polysaccharide;   

DOI  :  10.1590/S0103-50532007000100009

来源: SciELO

【 摘 要 】

Cashew gum (CG), an exudate polysaccharide from Anacardium ocidentale trees, was oxidized with TEMPO reagent and the 7product (CGOX) characterized by spectroscopic techniques (FT-IR and NMR), chromatographic analyses (HPLC and GPC), viscosity measurements and thermal analysis (TGA). The yield of the reaction product was 96%. The uronic acid content in starting gum (7.2 m%) was increased to 36 m%. The degree of oxidation based on free galactose and glucose units was 68%. NMR data show that oxidation occurred preferentially at primary carbons of galactose units. High degradation degree after oxidation was estimated by the difference on the expected and observed etaCGOX/etaCG ratio. The presence of organic and inorganic impurities in the new polyelectrolyte was detected by TGA. A less thermally stable cashew gum is formed after the oxidation with TEMPO based on initial decomposition temperature and IPDT.

【 授权许可】

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