Insights in starch acetylation in sub- and supercritical CO₂

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• 作者：Henky Muljana^a ; Francesco Picchioni^a ; Zeljko Knez^b ; Hero J. Heeres^a ; ^{H.J.Heeres@rug.nl"" rel=""nofollow} ; ^{h.j.heeres@chem.rug.nl"" rel=""nofollow} ; Leon P.B.M. Janssen^a
• 关键词：Acetylation ; Potato starch ; Starch acetate ; Phase behavior ; Supercritical CO₂
• 刊名：Carbohydrate Research
• 出版年：2011
• 出版时间：15 July 2011
• 年：2011
• 卷：346
• 期：10
• 页码：1224-1231
• 全文大小：742 K

文摘

An in-depth study on the acetylation of starch with acetic anhydride (Ac₂O) and sodium acetate (NaOAc) as the catalyst in pressurized carbon dioxide (scCO₂) in a broad pressure range (8–25 MPa) and a temperature of 90 °C is provided. Highest degrees of substitution (DS) of 0.29 (1 h reaction time) and 0.62 (24 h reaction time) were found near the critical point of the mixture (15 MPa). The phase behavior of the system CO₂, starch and acetic anhydride (Ac₂O) was studied in a high pressure view cell. The critical points were a clear function of the temperature and increased from the range of 9.4–10 MPa to 14.5–14.8 MPa when going from 50 to 90 °C (Ac₂O mole fraction at the critical point in the range of 0.08–0.09). Acetylation experiments with a range of starch particles sizes showed a clear relation between the DS and the particle size.