水相电位滴定法测定木质素的酚羟基和羧酸基含量  

Content determination of phenolic hydroxyl and carboxyl in lignin by aqueous phase potentiometric titration

作　　者：周明松[1,2] 黄恺[1,2] 邱学青[1,2] 杨东杰[1,2] 

机构地区：[1]华南理工大学化学与化工学院,广东广州510640 [2]广东省绿色化学产品技术重点实验室,广东广州510640

出　　处：《化工学报》2012年第1期258-265,共8页CIESC Journal

基　　金：国家杰出青年科学基金项目(20925622);国家自然科学基金项目(21006036);国家重点基础研究发展计划项目(2010CB732205)~~

摘　　要：引言木质素是自然界中仅次于纤维素的第二大可再生资源,是人类未来的主要资源来源[1]。以木质素为原料制备新材料和化工原料,逐步替代化石等日趋枯竭的不可再生资源。The potentiometric titration in aqueous phase is used for determination content of phenolic hydroxyl and carboxyl on alkali lignin（AL） and sodium lignosulphonate（SL）.The results show that the content of phenolic hydroxyl and carboxyl are 2.81 mmol·g-1 and 1.72 mmol·g-1 for AL,and 1.32 mmol·g-1 and 0.86 mmol·g-1 for SL,respectively.A comparison with classical non-aqueous potentiometric titration indicates that the stability is more excellent for the measurement in aqueous phase.The dynamic light scattering（DLS） method is used for the study of hydrodynamic diameter distributions of AL and SL in DMF and water solvents.The results show that they have stronger aggregation in DMF than in alkaline water,indicating that there is better dissolubility in alkaline aqueous solution than in DMF solvent.Therefore,it can be considered that the aqueous potentiometric titration is more suitable for the quantitative determination of phenolic hydroxyl and carboxyl contents on lignin-based compounds and can be an option for quantitative determination of the functional groups on lignin.

关 键 词：木质素 酚羟基 羧酸基 水相 电位滴定 

分 类 号：TQ041[化学工程]