离子液体水溶液中木质素溶解特性的微量热  

Dissolution properties of lignin in ionic liquid aqueous solutions:a microcalorimetry

作　　者：魏立纲 李贝 李明 高兴 马英冲 李坤兰 WEI Ligang;LI Bei;LI Ming;GAO Xing;MA Yingchong;LI Kunlan(School of Light Industry and Chemical Engineering,Dalian Polytechnic University,Dalian 116034,China)

机构地区：[1]大连工业大学轻工与化学工程学院,辽宁大连116034

出　　处：《大连工业大学学报》2018年第5期372-378,共7页Journal of Dalian Polytechnic University

基　　金：国家自然科学基金项目(21276034);辽宁省科学技术计划项目(201602058)

摘　　要：利用TAM Air等温微量热仪测量木质素在咪唑基离子液体及其水溶液中的溶解热,研究离子液体浓度、木质素浓度、温度及阴阳离子对木质素溶解过程的影响。结果表明,木质素在1-丁基-3-甲基咪唑醋酸盐([C_4C_1im]OAc)及其水溶液中溶解是放热过程。随着[C_4C_1im]OAc浓度增大,木质素溶解热和溶解焓增大。随着木质素浓度增大,在60%和80%[C_4C_1im]OAc水溶液中,溶解焓先增大后减小,分别在6.3%和4.8%达到最大值;[C_4C_1im]OAc中,溶解焓逐渐减小。温度由25℃升至35℃,60%[C_4C_1im]OAc中木质素溶解焓逐渐增大;在[C_4C_1im]OAc中,30℃时溶解焓最大。阴阳离子种类也影响木质素溶解,[OAc]^-的溶解焓大于[Cl]^-,[C_4C_1im]^+的溶解焓大于[C_2C_1im]^+。The dissolution heats of lignin in imidazolium ionic liquid or its aqueous solutions were measured using TAM Air isothermal microcalorimeter.Effects of ionic liquid concentration,lignin concentration,temperature,types of ions(anionic or cationic)on the dissolution process of lignin were comprehensively investigated.The results showed that the dissolution of lignin in 1-butyl-3-methyl-imidazolium acetate([C 4C 1im]OAc)and its aqueous solutions was an exothermic process.Both of the dissolution heat and enthalpy of lignin increased with the increase of[C 4C 1im]OAc concentration.With the increase of lignin concentration,the dissolution enthalpy of lignin was firstly increased and then decreased in 60%and 80%[C 4C 1im]OAc aqueous solutions,which reached the maximum values at 6.3%and 4.8%lignin concentration,respectively.However,the dissolution enthalpy of lignin in[C 4C 1im]OAc gradually decreased with the increasing of lignin concentration.The dissolution enthalpy of lignin in 60%[C 4C 1im]OAc was increased with elevating the temperature from 25 to 35℃,but the dissolution enthalpy of lignin in[C 4C 1im]OAc was the highest at 30℃.In addition,cationic and anionic ions also affected dissolution of lignin.The dissolution enthalpy of lignin in[OAc]-ionic liquid was greater than that in[Cl]^-,while it in[C 4C 1im]^+was greater than in[C 2C 1im]^+.

关 键 词：离子液体 木质素 溶解 微量热 

分 类 号：TS79[轻工技术与工程—制浆造纸工程] O642.1[理学—物理化学]