离子液体溶解细菌纤维素工艺优化及性能
Optimization of Dissolving Process and Properties of Bacterial Cellulose with Ionic Liquid
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摘要: 为提供一种新型高效的细菌纤维素(Bacterial cellulose,BC)溶解途径,本文以投料量、复合溶剂配比、溶解温度为实验因素,对离子液体咪唑类氯盐氯化-1-烯丙基-3-甲基-咪唑(1-allyl-3-methylimidazolium chloride,AmimCl)和1,3-二甲基-2-咪唑啉酮(DMI)溶解BC工艺进行优化,并对溶解后的BC进行再生处理,利用傅里叶红外光谱(Fourier transform infrared spectroscopy,FT-IR)、X-射线衍射(X-Ray Diffraction,XRD)、扫描电镜(Scanning Electron Microscope,SEM)及热重-差示扫描量热(Thermogravimetric Analysis-Differential Scanning Calorimetry,TG-DSC)对AmimCl溶解再生前后BC的化学基团、结晶度、表面形貌及热性能进行了分析。结果表明,离子液体AmimCl溶解BC最优工艺为:溶解温度为110 ℃,复合溶剂比为AmimCL:DMI=8:2,溶解时间为11 h,此条件下BC/IL溶液中BC质量分数可达6.5%。离子液体AmimCl溶解BC属于物理过程,不破坏其基本结构,溶解再生后的BC结晶度及热性能有所降低,纤维表面出现很多裂缝及孔洞,微纤丝堆积变得松散。本研究为BC实际应用过程中难溶解的问题提供了新的思路,为BC改性奠定了理论及技术基础。Abstract: In order to supply a new way of dissolving bacterial cellulose,inventory,ratio of double solvents,dissolving temperature were studied during BC dissolving in ionic liquid (1-allyl-3-methylimidazolium chloride,AmimCl). Meanwhile,the properties of BC before and after IL-dissolving were compared through Fourier Transform Infrared (FT-IR),X-ray diffraction (XRD),scanning electron microscope (SEM),and thermogravimetric analysis-differential scanning calorimetry (TG-DSC).According to the results of single factor experiments,the optimal dissolving process was determined as follows:dissolution temperature was 110℃,ratio of double solvents was 8:2 (AmimCl:DMI),dissolution time was 11 h,the mass fraction of BC in BC/IL solution could reach to 6.5%. The process of dissolving BC with Ionic liquid was a kind of physical process,which would not destroy the basic structure of BC. However,the crystallinity and thermal stability of BC after dissolving and regeneration decreased compared to BC before dissolving. More cracks and holes appeared on the surface of regenerated BC fiber,and the accumulation of micro fibers became loose. This study provided a new idea for BC dissolution during its practical application,and laid a theoretical and technical foundation for BC modification.