Configuration Transformation of Lignin in Wheat Straw Acid-Catalytic Ethanol Pulping Process

Configuration transformation of lignin in wheat straw acid-catalytic ethanol pulping process has been studied by the analysis of FT-IR1,H-NMR and GPC of milled wood lignin and ethanol lignin.The results indicate that syringyl and ρ-hydroxyphenyl propane units are easier to remove than guaiacyl propane unit in wheat straw acid-catalytic ethanol pulping process.Compared with milled wood lignin,ethanol lignin has less methoxyl group and aliphatic hydroxyl group,more phe-nolic hydroxyl groupl,ower molecular weight and narrower molecular weight distribution.