CHARACTERIZATION OF AUTOHYDROLYSIS ASPEN (POPULUS-TREMULOIDES) LIGNINS .1. COMPOSITION AND MOLECULAR-WEIGHT DISTRIBUTION OF EXTRACTED AUTOHYDROLYSIS LIGNIN
CHARACTERIZATION OF AUTOHYDROLYSIS ASPEN (POPULUS-TREMULOIDES) LIGNINS .1. COMPOSITION AND MOLECULAR-WEIGHT DISTRIBUTION OF EXTRACTED AUTOHYDROLYSIS LIGNIN
复制标题
DOI：
10.1139/v79-187
复制
发表时间：
1979-01-01
影响因子：
1.1
通讯作者：
WAYMAN, M
中科院分区：
文献类型：
--
作者：
CHUA, MGS;WAYMAN, M
无提取物的白杨木粕在195度下进行自水解。C作用5min ~ 2h，用90%二氧六烷提取木质素。与杨木粉磨木质素相比，自水解木质素的C含量较高，H和O含量较低。甲氧基含量也低于参比木质素。这些差异归因于非木质素成分的凝聚和并入木质素。结果表明，自水解时间为30 ~ 40 min时，木质素的最大脱木质素率为100%。从分子量分布研究来看，不同提取木质素的高分子量与低分子量材料的比例不同，在自水解时间为40 min时达到最大值。提出了木质素通过碳离子解聚/再聚的机理。对羟基苯甲酸被认为是一种阻断剂，有助于杨木木质素的可提取性。
Extractive-free aspen [Populus tremuloides] wood meal was subjected to autohydrolysis at 195.degree. C for 5 min to 2 h, and the lignin extracted with 90% dioxane. Extracted autohydrolysis lignin was higher in C but lower in H and O content than aspen milled wood lignin. The methoxyl content was also lower than the reference lignin. These differences were attributed to condensation and incorporation into the lignin of non-lignin components. A lignin extractability curve with a maximum delignification at autohydrolysis time of 30-40 min was found. From MW distribution studies the ratio of high MW to low MW materials varied for the different extracted lignins and reached a maximum at autohydrolysis time of 40 min. A mechanism of depolymerization/repolymerization of the lignin via carbonium ions was proposed. p-Hydroxybenzoic acid is postulated as contributing to the extractability of aspen lignin by acting as a blocking agent.