Structure and thermal behavior of a cellulose I-ethylenediamine complex.
Structure and thermal behavior of a cellulose I-ethylenediamine complex.
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DOI：
10.1021/bm8006709
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发表时间：
2008-09
影响因子：
6.2
通讯作者：
M. Wada;G. Kwon;Y. Nishiyama
中科院分区：
文献类型：
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作者：
M. Wada;G. Kwon;Y. Nishiyama
我们制备了高度结晶的样品的纤维素I-乙二胺（EDA）复合物的取向膜的海藻（刚毛藻）纤维素微晶在EDA中在室温下浸泡了几天。晶胞参数确定为a = 0.455，B = 1.133，c = 1.037 nm（纤维重复），γ = 94.02度。空间群为P2（1）。基于晶胞、密度和热重分析，不对称单元由一个无水葡萄糖残基和一个EDA分子组成。用X-射线衍射研究了纤维素I-EDA复合物的化学稳定性和热稳定性。当纤维素I-EDA复合物在室温下浸入甲醇或水中时，分别获得纤维素III I或I β。然而，在非极性溶剂如甲苯中浸泡并不影响配合物的晶体结构。纤维素I-EDA复合物在高达约130 ℃的温度下是稳定的，而EDA的沸点为117 ℃。该复合物的热稳定性可能是由EDA分子与纤维素之间的分子间氢键引起的。当加热到150摄氏度以上时，纤维素I-EDA复合物分解成纤维素I β。
We prepared highly crystalline samples of a cellulose I-ethylenediamine (EDA) complex by immersing oriented films of algal (Cladophora) cellulose microcrystals in EDA at room temperature for a few days. The unit-cell parameters were determined to be a = 0.455, b = 1.133, and c = 1.037 nm (fiber repeat) and gamma = 94.02 degrees. The space group was P2(1). On the basis of unit cell, density, and thermogravimetry analyses, the asymmetric unit is composed of one anhydrous glucose residue and one EDA molecule. The chemical and thermal stabilities of the cellulose I-EDA complex were also investigated by the use of X-ray diffraction. When the cellulose I-EDA complex was immersed in methanol or water at room temperature, cellulose III I or I beta was obtained, respectively. However, immersion in a nonpolar solvent such as toluene did not affect the crystal structure of the complex. The cellulose I-EDA complex was stable up to a temperature of approximately 130 degrees C, whereas the boiling point of EDA is 117 degrees C. This thermal stability of the complex is probably caused by intermolecular hydrogen bonds between EDA molecules and cellulose. When heated above 150 degrees C, the cellulose I-EDA complex decomposed into cellulose I beta.