溶出温度对乙醇木质素超临界解聚特性影响研究

通过控制溶出温度(160、180和200℃),制备了三种毛竹乙醇木质素EOL(EOL-160、EOL-180和EOL-200),并采用红外光谱仪(FT-IR)、凝胶渗透色谱(GPC)和热重分析(TG)分别对乙醇木质素的官能团、分子量分布及热稳定性进行了分析;采用微型高温高压反应釜,在超临界乙醇体系,进行三种乙醇木质素的解聚实验,通过气相色谱/质谱联用仪(GC/MS)及FT-IR对解聚产物进行分析,探讨乙醇木质素特性对其超临界乙醇环境解聚产物组成的影响规律。结果表明,随着溶出温度的升高,乙醇木质素溶出率呈上升趋势。EOL-160、EOL-180和EOL-200三种乙醇木质素在超临界条件解聚液相产物主要成分分别为对乙基苯酚、2,6-二甲氧基苯酚和4-羟基-3-甲氧基-苯甲酸酯。

Effect of extraction temperature on depolymerization characteristics of ethanol organosolv lignin in supercritical ethanol

Effect of extraction temperature (160, 180 and 200 ℃) on depolymerization characteristics of ethanol organosolv lignin (EOL) was investigated with a micro autoclave reactor. Three different EOLs (EOL-160,EOL-180 and EOL-200) were prepared by controlling extraction temperature, and their properties including functional groups, molecular weight distribution and thermogravimetric properties were analyzed by infrared spectroscopy (FT-IR), gel permeation chromatography (GPC) and thermogravimetric analysis (TG). The liquid and solid products obtaining from EOLs depolymerized in supercritical ethanol were analyzed by gas chromatography/mass spectrometry (GC/MS) and FT-IR, respectively. The results show that the main phenolic compound product for EOL-160, EOL-180 and EOL-200 depolymerized in supercritical ethanol were paraethyl phenol, 2,6-dimethoxy phenol and 4-hydroxy-3-methoxy-benzoate, respectively.