桉木木素的付立叶变换红外光谱研究

FTIR study of lignin from Eucalyptus

付立叶变换红外光谱是分析木素结构的一种有效手段。本研究用付立叶变换红外光谱法分析了桉木分离木素和桉木原本木素，并对两者进行了比较。结果表明桉木磨木木素由愈创木基和紫丁香基组成，其中紫丁香基占40％～45％，愈创木基占55％～60％，甲氧基含量为每C9单元1．40个左右。与杉木和山毛榉相比，桉木磨木木素中含有较多的乙酸基和共轭羰基，并且含有一定量的芳香酸的酯类。用差示光谱法对桉木原本木素进行了研究，结果表明原本木素比磨木木素含有更多的氢键联接和乙酸基，但原本木素中的α-羰基含量较少，紫丁香基结构单元的比例也较小，结果还表明磨木木素可能更多地来源于木材纤维细胞次生壁。

The isolated lignin (MWL) and protolignin of Eucalyptus Leichow No. 1 were studied by Fourier transform infrared (FTIR) spectroscopy. The result showed that the lignin of E. Leichow No. 1 was composed of sytingyl unit (s) and guaiacyl unit (G).The syringyl unit content was 40%-45%. The guaiacyl unit content was 55%-60%,Comparing with spruce and beech MWL, the lignin of E. Leichow No. 1 contained more acetyl and conjugated carbonyl. The result also showed that the syringyl unit and acarbonyl content were higher in MWL than in protolignin, while the protolignin contained more acetyl group. The MWL might contain more lignin fraction that came from fiber secondary wall (S2) 。