蚕丝在功能化离子液体中的溶解与再生

Dissolubility of the Silk Fibroin in the Functionalized Ionic Liquid

功能化离子液体氯化1-(2-羟乙基)-3-甲基咪唑是蚕丝的优良溶剂,在70℃时对脱胶蚕丝的溶解能力达到5.2%左右。向离子体液蚕丝溶液中加入甲醇可获得再生蚕丝。用数码相片、傅里叶变换红外光谱、扫描电镜和热重分析对再生蚕丝进行了表征。数码相片显示,经研磨后的再生蚕丝外观与脱胶蚕丝一样;扫描电镜表明再生蚕丝和脱胶蚕丝的微观结构基本一致,主要为5μm～10μm蚕丝纤维缠绕组成;再生蚕丝和脱胶蚕丝的傅里叶变换红外光谱谱图相同。实验表明,功能化离子液体是蚕丝的直接溶剂;热重分析数据表明再生蚕丝的分解温度略低于天然脱胶蚕丝,分解残留略高于天然脱胶蚕丝。对溶解机理进行了初步探讨。

The functionalized ionic liquid 1-（2-hydroxylethyl）-3-methylimidazolium chloride was found to be a novel and an excellent solvent for silk fibroin with the dissolubility of 5.2% at 70 ℃. The regenerated silk fibroin was obtained from the silk fibroin ionic liquid solution by coagulating with methanol and characterized by digital photograph, FT-IR, SEM and TGA. The digital photograph shows the regenerated silk fibroin after grinding has the same appearance with the original degumming silk; SEM image also shows the morphology are almost unchanged, which displaying a rough, but conglomerate texture composed by fibroin filber at 5 μm--10 μm; the FT-IR spectra of the regenerated silk fibroin and original degumming silk are basically the same. The experimental results show that functionalized ionic liquid is the direct solvent for silk fibroin, but the TGA data show the regenerated silk fibroin exhibit lower thermal stability and much more residues of thermal decomposition than that of original silk fibroin. The mechanism of the dissolution process of the silk fibroin in functionalized ionic liquid was also discussed.