碱木质素的甲基化改性降色及浅色微球制备  

Methylation of Alkali Lignin for Color Reduction Toward the Preparation ofLight-colored Microspheres

作　　者：张倩 李赢 ZHANG Qian;LI Ying(School of Chemical and Material Engineering,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学化工与材料工程学院,江苏无锡214122

出　　处：《林产化学与工业》2025年第2期103-108,共6页Chemistry and Industry of Forest Products

基　　金：江苏省科技计划重点研发项目(BE2020381)。

摘　　要：以硫酸二甲酯对从造纸黑液提取的碱木质素(AL)进行甲基化改性,封闭酚羟基避免形成醌型发色结构,从而实现降色。通过单因素试验得到甲基化改性降色的最优条件为:硫酸二甲酯用量是AL的60%,反应时间2 h,反应温度80℃。此时,甲基化木质素(MAL)在400 nm处白度提升25.81%,450 nm处白度提升31.76%。经差示紫外法测量酚羟基含量,碱木质素含酚羟基3.175 mmol/g,甲基化改性后下降至0.875 mmol/g。通过以0.5 mL/min速度向甲基化反应后的混合物中滴加2 mol/L的HCl溶液,制备MAL微球,微球尺寸分布最均匀,粒径约在0.4~0.9μm之间,其颜色进一步变浅。The alkali lignin(AL)extracted from paper black liquor was methylated with dimethyl sulfate to block the phenol hydroxyl group to avoid forming quinone type dark structure to achieve reduction.The optimal conditions for color reduction by methylation were as follows:the amount of dimethyl sulfate was 60%of AL,the reaction time was 2 h,and the reaction temperature was 80℃.Under this condition,the whiteness of methylated lignin(MAL)increased by 25.81%at 400 nm and 31.76%at 450 nm.The content of phenol hydroxyl in lignin was measured by differential ultraviolet methods,and the content of phenol hydroxyl in lignin was 3.175 mmol/g,which decreased to 0.875 mmol/g after methylation.MAL microspheres were prepared by adding 2 mol/L HCl solution to the methylation reaction products at a rate of 0.5 mL/min.The size distribution of the microspheres was the most uniform,the particle size was about 0.4-0.9μm,and it's color lightened further.

关 键 词：碱木质素 酚羟基封闭 甲基化改性 颜色 木质素微球 

分 类 号：TQ35[化学工程]