本文選題：離子液體 + 纖維素��； 參考：《福建農(nóng)林大學(xué)》2017年碩士論文

【摘要】：離子液體作為"綠色"溶劑,在溶解纖維素方面的研究取得了很大進(jìn)展,但第二大天然高分子材料——?dú)ぞ厶窃陔x子液體中的溶解研究還鮮有報(bào)道,并且現(xiàn)有離子液體存在熔點(diǎn)高、黏度高、穩(wěn)定性差等缺點(diǎn)。因此,開(kāi)發(fā)新型高效并且對(duì)纖維素與殼聚糖都具有良好溶解能力的離子液體成為必然趨勢(shì)。本文通過(guò)分子動(dòng)力學(xué)模擬以及溶劑化顯色參數(shù)等手段,研究極性非質(zhì)子溶劑與[AMIM]C1對(duì)纖維素的協(xié)同溶解作用,探討纖維素在離子液體中的可能溶解機(jī)理,為新型離子液體的合成提供理論指導(dǎo)。在此基礎(chǔ)上,設(shè)計(jì)合成了一種新型咪唑醋酸鹽離子液體,系統(tǒng)地研究了該離子液體的結(jié)構(gòu)、物理化學(xué)性質(zhì)、對(duì)纖維素及殼聚糖溶解性能以及回收等工作。主要內(nèi)容包括:首先,采用分子動(dòng)力學(xué)模擬、溶劑化顯色參數(shù)等手段研究了離子液體[AMIM]C1與極性非質(zhì)子溶劑二甲基亞砜(DMSO)、N,N-二甲基甲酰胺(DMF)、N,N-二甲基乙酰胺(DMAC)以及乙腈(ACN)組成的二元體系對(duì)纖維素的溶解過(guò)程,探究了[AMIM]Cl[AMIM]C1及有機(jī)溶劑復(fù)配體系對(duì)纖維素的溶解機(jī)理;結(jié)果表明,極性非質(zhì)子有機(jī)溶劑的加入可提高離子液體對(duì)纖維素的溶解能力。纖維素的溶解度會(huì)隨混合體系中極性非質(zhì)子有機(jī)溶劑含量的增加先增大后減小,其中[AMIM]C1/DMSO體系在質(zhì)量比為3:1時(shí)的溶解效果最佳。再生后的纖維素晶型由I型變?yōu)镮I型,且熱穩(wěn)定性下降。其次,設(shè)計(jì)合成了一種帶有雙烯丙基的咪唑醋酸鹽離子液體——1,3-二烯丙基-2-乙基咪唑醋酸鹽。采用FT-IR、HNMR對(duì)其分子結(jié)構(gòu)進(jìn)行表征,分析了新型離子液體的物理化學(xué)性質(zhì)及對(duì)纖維素、殼聚糖的溶解性能;結(jié)果表明,含有兩個(gè)烯丙基的離子液體會(huì)發(fā)生共軛效應(yīng),其電導(dǎo)率高于含有單個(gè)烯丙基的離子液體。該離子液體對(duì)纖維素和殼聚糖具有良好的溶解能力,并可同時(shí)溶解纖維素與殼聚糖,纖維素由I型變?yōu)镮I型,殼聚糖由α型變?yōu)棣滦�。同時(shí)探索了極性非質(zhì)子溶劑(DMSO)的加入對(duì)新型離子液體溶解能力的影響。結(jié)果表明,DMSO的加入會(huì)促進(jìn)1,3-二烯丙基-2-乙基咪唑醋酸鹽離子液體對(duì)纖維素的溶解,且在離子液體與DMSO的質(zhì)量比為3:1時(shí),其溶解效果最佳。但DMSO的加入會(huì)阻礙殼聚糖在1,3-二烯丙基-2-乙基咪唑醋酸鹽離子液體中的溶解。最后,使用活性炭吸附回收離子液體,研究了活性炭對(duì)離子液體1,3-二烯丙基-2-乙基咪唑醋酸鹽的吸附效果,考察了活性炭用量、離子液體濃度、吸附溫度、吸附時(shí)間以及活性炭使用次數(shù)對(duì)吸附性能的影響,探究無(wú)機(jī)鹽硫酸鈉的添加對(duì)吸附過(guò)程的影響。結(jié)果表明,當(dāng)活性炭用量8g/L,硫酸鈉用量240g/L,溫度30℃左右,吸附時(shí)間2h的條件下,活性炭對(duì)質(zhì)量濃度為80 mg/L的1,3-二烯丙基-2-乙基咪唑醋酸鹽水溶液的吸附率可達(dá)到99%以上,再生回收率可達(dá)93%。硫酸鈉的加入能促進(jìn)離子液體與水相的分離,提高活性炭對(duì)離子液體的吸附效果。
[Abstract]:As a "green" solvent, ionic liquids have made great progress in the dissolution of cellulose, but the dissolution of chitosan, the second largest natural polymer material, in ionic liquids has not been reported. And the existing ionic liquids have the shortcomings of high melting point, high viscosity and poor stability. Therefore, it is an inevitable trend to develop new ionic liquids with high efficiency and good solubility to cellulose and chitosan. In this paper, the synergistic dissolution of cellulose by polar non-proton solvent and [AMIM] C1 was studied by means of molecular dynamics simulation and solvation coloration parameters, and the possible dissolution mechanism of cellulose in ionic liquid was discussed. It provides theoretical guidance for the synthesis of new ionic liquids. On this basis, a new imidazole acetate ionic liquid was designed and synthesized. The structure, physical and chemical properties, solubility of cellulose and chitosan and recovery of the ionic liquid were systematically studied. The main contents are as follows: first, molecular dynamics simulation is used. The dissolving process of cellulose in the binary systems composed of ionic liquid [AMIM] C1 and polar non-proton solvent DMSO-N- (N-dimethylformamide) and acetonitrile (acetonitrile) has been studied by means of solvation coloration parameters, and the results are as follows: (1) the solubility of cellulose in the binary system composed of [AMIM] C1 and dimethyl sulfoxide dimethyl sulfoxide (DMSO), a polar non-proton solvent, has been studied. The dissolution mechanism of cellulose by [AMIM] Cl [AMIM] C1 and organic solvent was studied, the results showed that the solubility of ionic liquid to cellulose could be improved by adding polar non-proton organic solvent. The solubility of cellulose increases at first and then decreases with the increase of the content of polar non-proton organic solvent in the mixed system. The solubility of [AMIM] C1/DMSO system is the best when the mass ratio is 3:1. After regeneration, the crystalline form of cellulose changed from type I to type II, and the thermal stability of the regenerated cellulose decreased. Secondly, a diallyl imidazole acetate ionic liquid was designed and synthesized. The molecular structure was characterized by FT-IRN HNMR, the physical and chemical properties of the new ionic liquids and their solubility to cellulose and chitosan were analyzed, the results showed that conjugation effect occurred in ionic liquids containing two allyl groups. Its conductivity is higher than that of ionic liquids containing a single allyl group. The ionic liquid can dissolve cellulose and chitosan at the same time. Cellulose changes from type I to type II and chitosan from type 偽 to type 尾. At the same time, the influence of the addition of polar non-proton solvent (DMSO) on the solubility of new ionic liquids was investigated. The results show that the addition of DMSO can promote the dissolution of cellulose by ionic liquids of 1 ~ 3-diallyl -2-ethylimidazolium acetate, and the dissolution effect is the best when the mass ratio of ionic liquid to DMSO is 3:1. However, the addition of DMSO hinders the dissolution of chitosan in 1: 3-diallyl-2-ethyl imidazole acetate ionic liquids. Finally, the adsorption effect of activated carbon on ionic liquid (1) 3-diallyl -2-ethylimidazole acetate was studied. The amount of activated carbon, the concentration of ionic liquid and the adsorption temperature were investigated. The influence of adsorption time and times of activated carbon on adsorption performance and the effect of addition of inorganic salt sodium sulfate on adsorption process were investigated. The results show that when the amount of activated carbon is 8g / L, the amount of sodium sulfate is 240g / L, the temperature is about 30 鈩，

本文編號(hào)：1791792