林业工程学报2017，Vol.2Issue(3)：90-96,7.DOI:10.13360/j.issn.2096-1359.2017.03.015
工业碱木质素羟甲基化改性研究
Study on hydroxymethylation of industrial lignin
摘要
Abstract
Lignin is a natural polymer that can be used as a raw material for the preparation of chemicals and materials.Hydroxymethylation is an effective modification method to increase the activity of the lignin and therefore improve the utilization of the lignin.This study compared the structure changes of lignin before and after the hydroxymethylation reaction to evaluate the improvement of the activity of lignin.The structures of the hydroxymethylated lignin and the raw lignin were characterized by FTIR,DEPT 135 and HSQC.In addition,the hydroxymethylation reaction was optimized by orthogonal design with altering the conditions including temperature,time,pH,and the mass ratio of lignin to formaldehyde.The results showed that the C7 and C8 in p-coumaric acid units (PCA) and ferulic acid units (FA),the C3 and C5 in p-hudroxyphenyl units,and the C5 inguaiacyl units (G) reacted with formaldehyde to formhydroxymethyl groups.This hydroxymethylation reactions mairdy included Prings reaction and Lederer-Manasse reaction.However,other units,such as syringyl units (S),β3-O-4 aryl ether linkages (A) and phenylcoumarane substructure (C),did not react with formaldehydeunder alkaline conditions.The optimal conditions of hydroxymethylation were under the reaction temperature of 80℃,reaction time of 3 h,the pH of 11 and the mass ratio of alkali lignin to formaldehyde of 6 ∶ 1,where the hydroxymethyl content reached 2.32％.This study explained the changes in the structure of the alkali lignin after hydroxymethylation,and the results could be helpful to promote the application of industrial alkali lignin.关键词
羟甲基化/碱木质素/核磁共振/游离甲醛/正交试验Key words
hydroxymethylation/alkaline lignin/NMR/free formaldehyde/orthogonal array experiment分类
化学化工引用本文复制引用
徐强,孙倩倩,赵新坤,曹胜磊,佘雕,孙润仓..工业碱木质素羟甲基化改性研究[J].林业工程学报,2017,2(3):90-96,7.基金项目
国家自然科学基金(31370368) （31370368）
国家“十二五”科技支撑计划课题(2015BCA01B01). （2015BCA01B01）
