微波和离子液体辅助乙二醇提取椰壳木质素

Extraction of coconut shell lignin by ethylene glycol with aid of microwave radiation and ionic liquid

椰壳纤维中木质素质量分数很高,约为38%。以椰壳纤维为原料,在微波加热条件下,以离子液体辅助乙二醇为萃取剂提取椰壳纤维中的木质素。得最佳反应条件:微波反应功率为0.4 k W,提取时间为25 min,乙二醇体积分数为95%,离子液体投放量为1 g,在最佳条件下得到的木质素产率可达72%。对得到的木质素进行红外光谱分析、热重分析、紫外光谱分析。结果表明,乙二醇处理后的纤维物质中木质素、半纤维素质量分数大大降低;紫外和红外光谱分析表明,提取的木质素保持了原有的木质素结构。

The mass content of lignin in coconut shell fiber is as high as around 38%.Coconut shell fiber is used as raw materials to extract lignin under microwave heating with ionic liquid-assisting ethylene glycol as extractant. The optimal reaction conditions are obtained as follows： microwave reaction power is 0. 4 k W,extraction time being 25 min,volumetric content of ethylene glycol 95% and dosage amount of ionic liquid 1 g.The yield of lignin can reach 72% under the optimum conditions. The prepared lignin is analyzed by infrared spectrum,thermogravimetric analysis and UV spectrum analysis.The results show that the content of lignin and hemicellulose in the fiber treated by ethylene glycol is greatly reduced. Analysis results by ultraviolet and infrared spectra show that the extracted lignin retains the original lignin structure.