微晶纤维素在磷酸中的溶解——分子变化与动力学。

Department of Resources Science and Engineering, State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, Guangdong Province, China.

Molecules. 2009 Dec 4;14(12):5027-41. doi: 10.3390/molecules14125027.

In this study, we aimed to dissolve microcrystalline cellulose (MCC) with phosphoric acid to obtain high-quality fermentable saccharides. MCC was directly dissolved in phosphoric acid (the concentration was 83%) for 10 hours at temperatures of 30, 50, and 70 degrees C. The structural changes of MCC were determined in detail with X-ray powder diffraction, solid-state cross-polarization magic angle spinning (13)C-NMR, and X-ray photoelectron spectroscopy. The kinetics of MCC decrystallization during treatment with phosphoric acid was also compared at 30, 50, and 70 degrees C. With the assumption of first order kinetics, the Arrhenius parameters of K, A(0) and E(a) were calculated. The rate constants of decrystallization reaction (K) were 0.06, 0.17, and 0.12 h(-1) respectively. The pre-exponential factor (A(0)) was 1.2 x 10(6) h(-1), and the activation energy (E(a)) was 42.4 kJ/mol.

在这项研究中，我们旨在利用磷酸溶解微晶纤维素（MCC），以获得高质量的可发酵糖。MCC 直接溶解在 83%浓度的磷酸中，在 30、50 和 70°C 下反应 10 小时。用 X 射线粉末衍射、固态交叉极化魔角旋转（13）C-NMR 和 X 射线光电子能谱详细确定了 MCC 的结构变化。还比较了在 30、50 和 70°C 下磷酸处理过程中 MCC 脱结晶的动力学。假设一级动力学，计算了 K、A(0)和 E(a)的 Arrhenius 参数。脱结晶反应的速率常数（K）分别为 0.06、0.17 和 0.12 h(-1)。指数前因子（A(0)）为 1.2 x 10(6) h(-1)，活化能（E(a)）为 42.4 kJ/mol。