水热法制备羟甲基化木质素工艺研究  

Methylolation of Lignin by Hydrothermal Method

作　　者：宋艳 宗旭[1,2] 张鑫 单雪影 李锦春[1,2] SONG Yan;ZONG Xu;ZHANG Xin;SHAN Xueying;LI Jinchun(School of Materials Science and Engineering,Changzhou University,Changzhou 213164,China;Jiangsu Key Laboratory of Environmentally Friendly Polymer Materials,Changzhou University,Changzhou 213164,China;School of Environmental and Safety Engineering,Changzhou University,Changzhou 213164,China)

机构地区：[1]常州大学材料科学与工程学院,江苏常州213164 [2]江苏省环境友好高分子材料重点实验室(常州大学),江苏常州213164 [3]常州大学环境与安全工程学院,江苏常州213164

出　　处：《常州大学学报（自然科学版）》2021年第2期8-16,共9页Journal of Changzhou University：Natural Science Edition

基　　金：国家自然科学基金面上资助项目(51473024);中国石油化工股份有限公司科研资助项目(2180184)。

摘　　要：为了改进碱木质素羟甲基化的制备方法,采用水热法对碱木质素(Lig)进行羟甲基化改性,利用FT-IR半定量法测得的羟甲基含量作为参考指标,并结合产率,确定了最佳工艺条件为:反应温度100℃、反应时间2 h、m(Lig)∶m(HCHO)为6∶1,m(Lig)∶m(NaOH)为24∶1,该工艺条件下所得羟甲基化木质素(Lig—OH)的羟甲基相对含量为0.95,比改性前Lig增加了0.27,产率为98.3%。核磁共振氢谱(1 H NMR)与热失重(TGA)的分析结果表明Lig—OH的羟甲基含量和酚羟基均有所提高,且其初始降解温度(t 5%)较Lig提高了38℃,500℃下的残留量更是提高了33.6%,所得羟甲基化木质素表现出良好的热稳定性能和成炭能力,有望作为成炭剂用于膨胀型阻燃高分子材料领域。In order to improve the preparation method of alkali lignin methylolation,the methylolation of alkali lignin was carried out by hydrothermal method,and the process was investigated with the methylol content measured by infrared Fourier transform(FT-IR)semi-quantitative method accompanied with the product yield as a reference index.The proper process conditions are as follows:the reaction temperature 100℃,the reaction time 2 h,the mass ratio of alkali lignin to formaldehyde 6∶1,as well as the mass ratio of alkali lignin to sodium hydroxide 24∶1,and under the process conditions the relative content of methylol groups in lignin(Lig—OH)obtained was 0.95,which increased by 0.27 higher than that of unmodified lignin(Lig),and the yield was 98.3%.In addition,the results of nuclear magnetic resonance spectroscopy(1 H NMR)and thermogravimetric analysis(TGA)showed that for Lig—OH,the enhancement of the relative content of hydroxymethyl groups,was accompanied with the increase of phenolic hydroxyl groups,and its initial degradation temperature(t 5%)was as high as 249℃,compared with the original alkali lignin(Lig)increased by 38℃,meanwhile the residual amount at 500℃reached 40.8%,significantly higher than that of 7.2%.Lig—OH exhibits good thermal stability and char-forming ability,and it is expected to be used as a charring agent in the field of intumescent flame-retardant polymer materials.

关 键 词：水热法 木质素 羟甲基化 半定量法 热稳定性能 

分 类 号：TQ314.1[化学工程—高聚物工业]