College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Carbohydr Polym. 2013 Jan 30;92(1):11-8. doi: 10.1016/j.carbpol.2012.09.059. Epub 2012 Oct 2.
In this study, purified bamboo cellulose was used to synthesize cellulose diacetate (B-CDA). The synthesis was controlled by determination of the degree of substitution and insoluble residue content. The product then was characterized by FTIR. The rheological properties of B-CDA solutions in acetone/N,N-dimethylacetamide (DMAc) solvent system were systematically investigated on an advanced rheometer, including the dependence of apparent viscosity η(α), non-Newtonian index n, and structural viscosity index Δη on the concentration and temperature of the solutions. B-CDA-acetone/DMAc solution is a shear-thinning fluid. With increasing solution concentration and decreasing temperature, Δη increased, whereas n decreased, which indicates a deteriorating spinnability. Moreover, the values of the viscous flow activation energy E(η) based on the Arrhenius equation increased when the shear rate γ was enhanced, which indicates that the η(α) of the solution is more sensitive to temperature in the higher γ values. The results are favorable for predicting the B-CDA solution spinnability.
在这项研究中，使用纯化的竹纤维素合成了纤维素二醋酸酯（B-CDA）。通过测定取代度和不溶性残渣含量来控制合成。然后通过傅里叶变换红外光谱（FTIR）对产物进行了表征。在高级流变仪上系统地研究了 B-CDA 在丙酮/N,N-二甲基乙酰胺（DMAc）溶剂体系中的溶液的流变性质，包括表观粘度 η（α）、非牛顿指数 n 和结构粘度指数 Δη 对溶液浓度和温度的依赖性。B-CDA-丙酮/DMAc 溶液是一种剪切稀化流体。随着溶液浓度的增加和温度的降低， Δη 增加，而 n 减小，这表明可纺性变差。此外，基于阿伦尼乌斯方程的粘性流活化能 E（η）的值随着剪切速率 γ 的增加而增加，这表明在较高的 γ 值下，溶液的 η（α）对温度更敏感。这些结果有利于预测 B-CDA 溶液的可纺性。
