【作者】 张燕如； 宋艳娜； 董瑞雪； 樊永明；

【Author】 ZHANG Yan-ru;SONG Yan-na;DONG Rui-xue;FAN Yong-ming;Key Lab of Lignocellulosic Fibers Utilization,College of Materials Science and Technology,Beijing Forestry University;

【机构】 北京林业大学材料科学与技术学院木质纤维的利用重点实验室；

【摘要】 以苯酚-水为溶剂,采用不同类型的催化剂对碱木质素进行了酚化改性,探讨了反应温度、反应时间、催化剂用量对酚化降解碱木质素酚羟基含量的影响,并采用凝胶渗透色谱(GPC)、超导核磁共振谱(~1H-NMR)对产物分子质量以及结构变化进行表征。结果表明,酸性强的催化剂催化活性强,催化产物的酚羟基含量高。以酚化降解产物的酚羟基含量为目标,初步优化的酚化条件为:催化剂为氯化铝,反应温度140℃,反应时间为2h,催化剂用量5%。碱木质素在酚化改性过程发生了脱甲氧基作用,木质素大分子中酚羟基基团增多,酚化降解产物的分子质量降低,多分散性减小。更多还原

【Abstract】 The alkali lignin was phenolic degraded by various catalysts.The results showed that the acidic catalysts was contributed to the increase of catalyst activity than alkaline catalysts.Higher phenol hydroxyl content was obtained with 5%of aluminium chloride on phenolwater mass as catalyst at 140 t for 2 h.The structure and molecular weight of the phenolic productions were studied through GPC and ’ HNMR.It was indicated that the demethylation by the phenolic modification made the increase of the phenol hydroxyl content in the alkali lignin.At the same time,the molecular weight was decreased in the process of phenolic modification,while the polydispersity was lower than that of the control.更多还原