木质纤维成分的乙酸分离方法及表征

研究了一种用含有少量硫酸的乙酸溶液分离杨木成分的方法。考察了反应时间、乙酸浓度、液比和催化剂浓度对木材成分分离的影响。对分离出的木材三种成分进行了表征。结果表明,分离杨木成分的较佳条件为:硫酸浓度0.3%,液比6,反应时间3h和乙酸浓度90%。残渣的主要成分是α-纤维素和半纤维素。水不溶沉淀物(乙酰化木质素)的重均分子量分布在341到253之间,分散性系数分布在1.1到1.2这一窄范围内。糖分析结果表明,可溶性成分主要来源于半纤维素,以单糖形式存在。

Isolation and characterization of wood components with aqueous acetic acid

A study was conducted on the isolation of poplar (Populus × euramaricana (Dode) Guineir cv. l-72/58) wood components with aqueous acetic acid (AcOH) containing small amounts of sulfuric acid. The reaction time, concentration of acetic acid, ratio of liquor to wood, and concentration of acid catalyst were investigated to examine their effects on the fractionation of wood components. The three main separated components were characterized. The results showed that the optimum conditions for fractionation of poplar wood components were: 0.3% H₂SO₄ in reaction solution, ratio of liquor to wood 6, reflux time 3 h, and 90% AcOH. The residues were mainly composed of α-Cellulose and hemicellulose. The water insoluble precipitate (acetic acid lignin, AcL) had a low weight-average molecular weight range from 341 to 253 (Mw) and a narrow molecular weight distribution from 1.1 to 1.2. The sugar analysis revealed the solubilized products resulted mainly from hemicellulose and exited as monosaccharides. Biography: LI Gai-yun (1974–), female, assistant professor in Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, P. R.