不同溶剂溶解制备纤维素溶液及其流变性能

Preparation and Rheological Properties of Cellulose Solutions from Different Solvents

中文关键词:  纤维素  溶液  溶剂体系  流变性能

中文摘要:

      分别采用N-甲基吗啉-N-氧化物（NMMO）、1-丁基-3-甲基咪唑氯盐（[BMIM]Cl）离子液体（ILS）、二甲基乙酰胺/氯化锂（DMAc/LiCl）、NaOH/尿素（Urea)以及传统的铜乙二胺（CED，铜氨法）和二硫化碳/氢氧化钠（CS₂/NaOH，黏胶法）6种不同的溶剂体系溶解纤维素得到均匀的纤维素溶液，研究相同条件下不同纤维素溶液的稳态和动态流变性能。结果表明，所有纤维素溶液均属于假塑性流体，表观黏度随剪切速率的增大而降低；CED和CS₂/NaOH溶剂体系制得的纤维素溶液加工性能相对较好，但对纤维素大分子的破坏性相对较强；NMMO和ILS溶剂体系制得的纤维素溶液加工性能相对较差，但对纤维素大分子的破坏性相对较小；DMAc/LiCl和NaOH/Urea溶剂体系制得的纤维素溶液的加工性能和对纤维素大分子的破坏性则介于传统溶剂体系（CED及CS₂/NaOH）和新型溶剂体系（NMMO及ILS）之间。

Abstract:

      Six different solvent systems including N-methylmorpholine-N-oxide (NMMO), 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) ionic liquid (ILS), dimethylacetamide/lithium chloride (DMAc/LiCl), NaOH/urea, traditional copper(II)-ethylenediamine complex (CED) and CS₂/NaOH were employed respectively to dissolve cellulose and different uniform cellulose solutions were obtained. Steady state and dynamic rheological properties of different cellulose solutions were investigated under the same condition. The results showed that all cellulose solutions were pseudoplastic fluids and the apparent viscosity decreased with the increasing of shear rate. The cellulose solutions prepared by CED and CS₂/NaOH had the relatively good processing performance, however the destructive effect on cellulose macromolecules was relatively strong. The cellulose solutions obtained through NMMO and ILS dissolution had relatively inferior processing performance with relatively weak destructive effect on cellulose macromolecules. The processing properties of the cellulose solution and the destructive effect on cellulose macromolecules obtained from DMAc/LiCl and NaOH/Urea solvents were between the traditional solvent systems(CED and CS₂/NaOH) and new type of solvent systems (NMMO and ILS).