甲酸/盐酸胍低共熔溶剂温和高效分离毛竹木质素  

Mild and efficient fractionation of moso bamboo lignin based on formic acid/guanidine hydrochloride deep eutectic solvent

作　　者：程鹏 郭宗伟 许阳蕾 李鑫 宋怡佳 许凤[1] CHENG Peng;GUO Zongwei;XU Yanglei;LI Xin;SONG Yijia;XU Feng(School of Materials Science and Technology,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学材料科学与技术学院,北京100083

出　　处：《精细化工》2022年第2期345-351,共7页Fine Chemicals

基　　金：国家重点研发计划项目(2019YFB1503804);高等学校学科创新引智计划项目(B21022);中央高校基本科研业务费专项资金(PTYX202141)。

摘　　要：以毛竹为原料,采用甲酸/盐酸胍低共熔溶剂(DES)温和高效分离木质素,并对其结构、热稳定性和抗氧化性进行了表征与测试。结果表明,甲酸/盐酸胍[n(甲酸)∶n(盐酸胍)=4∶1]DES实现了温和短时条件下(100℃,2 h)高效分离木质素(得率为59.31%),当进一步升温至120℃时,得率可达73.98%。原因是该酸性体系中氢质子使木质素中大量的β—O—4、β—β、β—5连接键断裂,促使木质素大分子解聚成小分子而溶出。分离的木质素质量分数高于96.6%,相对分子质量较低(Mw=1040~2040),多分散系数<1.5,结构均一,热稳定性好。同时,该木质素抗氧化活性较强[半抑制浓度(IC50)=0.016~0.045 g/L],优于商业抗氧化剂丁基羟基茴香醚(IC50=0.019 g/L)。Lignin from moso bamboo was separated mildly and efficiently using formic acid/guanidine hydrochloride deep eutectic solvent(DES).The structure,thermal stability and antioxidant activity of the lignin were characterized.It was found that formic acid/guanidine hydrochloride[n(formic acid)∶n(guanidine hydrochloride)=4∶1]DES resulted in a high lignin yield of 59.31%under mild conditions(100℃,2 h)and further increased to 73.98%at 120℃.This was attributed to the acidic DES donated active protons to selectively cleaveβ—O—4,β—β,β—5 bonds and further facilitated a large amount of lignin removal.The separated lignin had a high mass fraction(>96.6%),low relative molecular mass(Mw=1040~2040),low polydispersity index(PDI<1.5),homogeneous structure,excellent thermal stability.The antioxidant performance of the lignin[half maximal inhibitory concentration(IC50)=0.016~0.045 g/L]was better than that of the commercial antioxidant butylatedhydroxytoluence(IC50=0.019 g/L).

关 键 词：低共熔溶剂 毛竹 木质素分离 结构解析 抗氧化性能 分离提纯技术 

分 类 号：TQ352[化学工程] O636.2[理学—高分子化学]