Zhang Hui, Xu Yaoguang, Li Yuqi, Lu Zexiang, Cao Shilin, Fan Mizi, Huang Liulian, Chen Lihui
College of Materials Engineering, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China.
Nanocellulose and Biocomposites Research Centre, College of Engineering, Design and Physical Sciences, Brunel University London, Middlesex UB8 3PH, UK.
Polymers (Basel). 2017 Oct 18;9(10):526. doi: 10.3390/polym9100526.
A facile cellulose solvent 1,3-diallyl-2-ethylimidazolium acetate ([AAeim][OAc]) with high electrical conductivity has been designed and synthesized for the first time, via a quaternization reaction and ion exchange method. The dissolution characteristics of cellulose in this solvent were studied in detail. Meanwhile, the co-solvent system was designed by adding an aprotic polar solvent dimethyl sulfoxide (DMSO) in [AAeim][OAc]. The effects of temperature and the mass ratio of DMSO to [AAeim][OAc] on the solubility of cellulose were studied. Furthermore, the effects of regeneration on the molecular structure and thermal stability of cellulose were determined by Fourier transform infrared spectroscopy (FT-IR), thermal gravity analysis (TGA) and X-ray diffraction (XRD). The findings revealed that the synthesized ionic liquid (IL) has a relatively low viscosity, high conductivity and a good dissolving capacity for bamboo dissolving pulp cellulose (Degree of Polymerization: DP = 650). The macromolecular chain of the cellulose is less damaged during the dissolution and regeneration process. Due to the increased number of "free" anions [OAc] and cations [AAeim]⁺, the addition of DMSO can significantly increase the solubility of the cellulose up to 12 wt % at the mass ratio of 3:1, indicating that the synthesized IL has a potential application in the electrospinning field.
首次通过季铵化反应和离子交换法设计并合成了一种具有高电导率的简便纤维素溶剂1,3 - 二烯丙基 - 2 - 乙基咪唑醋酸盐（[AAeim][OAc]）。详细研究了纤维素在该溶剂中的溶解特性。同时，通过在[AAeim][OAc]中添加非质子极性溶剂二甲基亚砜（DMSO）设计了共溶剂体系。研究了温度以及DMSO与[AAeim][OAc]的质量比对纤维素溶解度的影响。此外，通过傅里叶变换红外光谱（FT - IR）、热重分析（TGA）和X射线衍射（XRD）确定了再生对纤维素分子结构和热稳定性的影响。研究结果表明，合成的离子液体（IL）具有相对较低的粘度、高电导率以及对竹溶解浆纤维素（聚合度：DP = 650）良好的溶解能力。纤维素的大分子链在溶解和再生过程中受损较小。由于“游离”阴离子[OAc]和阳离子[AAeim]⁺数量增加，在质量比为3:1时，添加DMSO可显著提高纤维素的溶解度至12 wt%，表明合成的离子液体在静电纺丝领域具有潜在应用。
