摘要
应用UV、FT-IR、GPC和GC-MS研究了不同制备方法提纯的慈竹磨木木质素(milledwoodlignin,MWL)的结构特性,结果表明慈竹木质素属于愈疮木醇-芥子醇-对香豆醇(GSH)型木质素,竹木质素侧链含有少量的α_β碳碳双键,慈竹中含有数量相当多的紫丁香基结构单元,且紫丁香基结构单元的含量高于愈疮木基结构单元的含量;慈竹木质素含有酯键,主要是对-香豆酸的羧基与酚羟基发生酯化反应生成的。经超声波辅助碱抽提的木质素相对分子质量分布比较均匀,乙醇抽提可以增加木质素的重均分子质量。慈竹木质素的紫丁香基单元(S_unit)存在大量的β_O_4的联接,竹木质素中松柏醇和松柏醛以及香豆醛和香豆酸的含量很少,木质素H单元的侧链γ_碳存在少量醚键联接,愈疮木基单元(G_unit)和S单元的侧链γ_碳不存在醚键联接。
The structures of three milled wood lignins(MWLs)prepared with different methods were examined using UV,FT-IR,GPC,and GC-MS.The different spectra indicated that,bamboo lignin belongs to'GSH'-Lignin.Its side chain contained a small amount of double bonds and the quantity of S_unitwas higher than that of G_unit.The amount of EL was higher than those of others whereas the polydispersity of UDL was lower than the other two.Ester bond in lignin was derived from coumaric acid and OH ph .Bamboo lignin conˉtainedresidual cinnamaldehyde(coniferaldehyde)and cinnamyl alcohol(coniferyl alcohol)endgroups.The perˉcentage ofβ_O_4ether bond was higher in S_unit than in G&S_units.There was no ether bond in G and S_ units of lignin and only a small amount of ether bonds was found in H_unit.
出处
《分析测试学报》
CAS
CSCD
北大核心
2005年第3期77-81,85,共6页
Journal of Instrumental Analysis
基金
863计划子项目资助(2002AA322050)
