基于催化水热预处理棉秆木质素分离及其结构表征

Separation and Characterization of Lignin Obtained by Catalytic Hydrothermal Pretreatment of Cotton Stalk

探究了不同催化水热体系对棉秆木质素的分离效果的影响。研究结果表明,基于Ni/H_2O和FeS/H_2O催化水热体系分离得到的棉秆木质素组分得率和纯度均较高。二维核磁谱图表明得到的木质素组分主要是以愈疮木基单元(G型)为主的愈疮木基(G型)-紫丁香基(S型)低分子量木质素片段,类似于典型的阔叶木。此外,棉秆木质素结构单元主要以β-O-4′的连接键连接,同时含有少量的β-β′和β-5′连接。

Isolation of lignin using different catalytic methods from cotton stalk was comparatively investigated in this study.The results showed that the yields and purities of obtained lignin samples using Ni/H_2O and FeS/H_2O catalytic hydrothermal pretreatments were relatively high as compared with other samples.2D NMR spectra demonstrated that guaiacyl（G）unit was predominant in these guaiacyl-syringyl（G-S）low molecular lignin fractions,which were similar to the typical lignin types of hardwood.Moreover,the obtained lignin fractions mainly consisted ofβ-O-4′aryl ether linkages,followed by small amounts of resinol（β-β′）and phenylcoumaran（β-5′）structures.