【摘要】 将离子液体氯化1-丁基-3-甲基咪唑([BMIM]Cl)、水、固体酸催化剂组成的混合溶剂应用于微晶纤维素的预处理过程中,并尝试把经过预处理的微晶纤维素应用于随后的溶剂液化的研究中,对经过混合溶剂处理后的微晶纤维素进行表征分析。通过测定纤维素的聚合度、官能团基变化、热重分析、结晶结构和表面结构等对微晶纤维素结构进行比较分析。通过对苯酚溶剂液化的基本表征、残渣物的结晶结构以及生成物相对分子质量的变化了解了混合溶剂对微晶纤维素的处理效果。结果表明,通过混合离子液体[BMIM]Cl和水并且添加固体酸催化剂形成新的混合溶剂体系对微晶纤维素进行预处理,发现溶剂在保留纤维素主要葡萄糖单元的同时能够有效地降低聚合度。聚合度从未处理时的190降到样品[B]Cl(10)的165和样品[B]Cl(10)+NR50的151。混合溶剂对非结晶或低结晶物质具有一定的溶解能力,并且对高结晶性纤维素部分的氢键结构起到破坏作用和造成整体结晶结构的歪曲。在随后的液化过程中,处理后的纤维素液化效率有所提高,在反应2 min时,固体酸加混合溶剂处理的微晶纤维素液化残渣率为19%,而未处理的液化残渣率29%。表明使用了混合溶剂添加固体酸的溶剂体系对加速液化的效果更佳,预处理对最终液化生成物的性质影响不大。更多还原

【Abstract】 Ionic liquid( IL)-water mixture solvent including solid acid catalysis NafionNR50 was applied in cellulose pretreatment process.The pretreated cellulose was used in the process of phenol solvent liquefaction.To obtain some information about the effects of IL-water on cellulose,the characteristic of pretreated cellulose samples was analyzed.The degree of polymerization( DP) value of pretreated cellulose was tested.X-ray diffraction( XRD),Fourier transform infrared( FT-IR) spectroscopy,Gel permeation chromatography( GPC),thermogravimetric / differential thermal analysis( TG-DTA) and scanning electron microscope( SEM) were used to describe the influence of IL-water mixture on cellulose.It was suggested that the significant effect of cellulose by IL-water mixture pretreatment was responsible for the destruction of crystalline structure,the reduction of DP and surface structure.The residues of pretreated cellulose were 19 %,and the of untreated one was 29%.The result of XRD and GPC analysis also confirmed that the effect of faster liquefaction was due to the pretreatment process.These comparative results indicated that the IL-water mixture had shown the potentiality for the biomass pretreatment using in the field of solvent liquefaction processes for biomass-base materials.更多还原