稻草木质素的硫酸法提取与表征

用硫酸法提取农作物废弃物稻草中的木质素,采用质量分数72%的硫酸,以15(mg)∶1(L)的液固单位比,室温下反应2 h,得到产率9.23%的木质素.利用扫描电镜(SEM)、综合热分析、傅里叶红外光谱(FTIR)和氢核磁共振波谱(¹H-NMR)分析手段表征木质素的物理性质和化学结构,结果表明:木质素呈表面粗糙且有大量孔隙的不规则块状结构,在175~700 ℃内发生热解,分子结构中存在着大量羟基、羰基和醚键等活性官能团,属于对羟基苯基-愈创木基-紫丁香基型木质素.

Extraction and characterization of the lignin from rice straw by sulfuric acid

In this work,lignin was extracted from rice straw by sulfuric acid.The brown lignin was obtained through extraction by 72% H₂SO₄ for 2 h at room temperature and the ratio of liquid to solid was 15.The content of lignin in rice straw was 9.23%.The lignin was analyzed using scanning electron microscope(SEM),thermogravimetric analysis and differential scanning calorimetry(TG-DSC),Fourier transform infrared spectroscopy(FT-IR)and proton nuclear magnetic resonance(¹H-NMR).It was showen that the lignin was irregular block,its surface was rough and lacunaris,and it had a good thermal stability,and the decomposition temperature of lignin was between 175 ℃ and 700 ℃.It contained many functional groups like hydroxyl,carbonyl,ether linkage and benzene ring structure and was composed of p-hydroxyphenyl lignin,guaiacyl lignin and syringyl lignin.