离子液体/羊毛纤维/凝固剂三元相图的构建

三元相图是研究羊毛角蛋白再生过程热力学行为的有效工具。通过浊度测试和Boom经验方程构建离子液体(IL)/羊毛纤维/凝固剂浊点线性关系(LCP)曲线和三元相图，进一步系统地研究了凝固剂种类、再生温度和离子液体结构对羊毛角蛋白再生性能的影响规律。结果表明，羊毛角蛋白最优再生体系是1-乙基-3-甲基咪唑磷酸二乙酯(Emim]Dep)/羊毛纤维/水(25℃)。对羊毛纤维原料和不同再生条件获得的再生羊毛角蛋白进行FT-IR和XRD表征，结果表明再生羊毛角蛋白的结构和羊毛纤维原料基本保持一致，但相对结晶度有所下降。实验温度为25℃时，以水为凝固剂制备的再生羊毛角蛋白相对结晶度最高。

The construction of phase diagram for ionic liquid/wool fiber/coagulator ternary systems

Keratin is one of the natural polymers with abundant reserves, wool fiber consists 95wt% of keratin, which is an important source of natural keratin and has excellent mechanical and biological properties. However, due to the numerous complex inter- and intra-molecular hydrogen bonds, disulfide bonds and other chemical bonds, wool fiber is insoluble in water and common organic solvents. As an emerging green solvent, ionic liquid (IL) shows outstanding performance in dissolving natural polymers such as wool fiber, cellulose, chitin, etc. due to their tunable structure, non-volatile, thermal stability, as well as high solubility for biopolymer. According to the reports, the current researches of ionic liquids on wool fiber are mainly focused on the solubility properties of wool fiber. The studies on the regeneration properties of wool keratin are still limited. There are three components involved in the regeneration process of wool fiber, and thus the thermodynamic behavior of polymer regeneration can be investigated by the ternary phase diagram. In this study, the linearized cloud point (LCP) correlation and ternary phase diagram of IL/wool fiber/coagulator (T) system were constructed by the turbidity method. The effects of coagulator types, coagulation temperatures, and structures of ILs on the properties of wool keratin regeneration were investigated systematically. The regenerated wool keratin was obtained using Emim]Dep as the solvent with the coagulation temperature of 25℃. In different coagulator systems, the order of wool keratin regeneration capacity is water>ethanol>iso-propanol. The regenerated wool keratin was obtained using Emim]Dep as the solvent, and water as the coagulator. In different coagulation temperature systems, as the coagulation temperature increased, the regeneration capacity of wool keratin gradually decreased. The regenerated wool keratin was obtained using water as the coagulator with a coagulation temperature of 25℃. In different IL structure systems, the order of wool keratin regeneration capacity was Emim]Dep>DBNE]Dep>DBNH]OAc. The characterization of raw wool fiber and regenerated wool keratin under different regeneration conditions were obtained by FT-IR and XRD, the characterization of the structures and properties showed that the main structure of the regenerated wool keratin basically agreed with the raw wool fiber, and the crystallinity of the regenerated wool keratin had decreased than raw wool keratin. The highest crystallinity of the regenerated wool keratin was obtained from the system of Emim]Dep/wool fiber/water system at the coagulation temperature of 25℃.