离子液体催化降解构皮木质素

Degradation of Lignin from Mulberry Bark Catalyzed by Ionic Liquids

以氯代正丁烷和N-甲基咪唑作为原料合成离子液体[Bmim]Cl,并用1H-NMR和13C-NMR表征其结构。将合成的离子液体用于构皮木质素脱除的研究,并在离子液体-乙醇-水三元体系中进行条件优化。结果表明,构皮木质素脱出率最大为78.46%,其优化条件为水体积10 mL、原料与催化剂比5∶4、反应温度70℃及反应时间6 h。借助FT-IR、SEM等对降解后的残渣进行测试,可明显看出经离子液体处理前后的残渣结构的不同。且GC-MS图分析萃取液中有酚类小分子和较多甲氧基含量的物质,表明离子液体能有效促进构树皮木质素的降解,使木质素大分子结构解构。

Ionic liquids [Bmim]Cl were synthesized from N-methylimidazole and chloro-n-butane. The structures were characterized by 1 H-NMR, 13 C-NMR. The synthesized ionic liquids were used to study the lignin removal from paper mulberry bark, and the conditions were optimized in the ternary system of ionic liquid-ethanol-water. The results showed that the highest lignin removal rate was 78.46%. The optimal conditions were as follows: water volume 10 mL, raw material to catalyst volume ratio 5∶4(g/mL), reaction temperature 70 ℃ and reaction time 6 h. By means of FT-IR, SEM and other test methods, it can be seen that the structure of the residue before and after ionic liquid treatment was different and GC-MS analysis of phenolic small molecules and more methoxyl content of substances. The results showed that ionic liquids could effectively promote the degradation of lignin from the bark and deconstruct the macromolecular structure of lignin.