聚离子液体催化碳酸乙烯酯与甲醇的酯交换反应  

Efficient Synthesis of Dimethyl Carbonate via Transesterification of Methanol and Ethylene Carbonate Catalyzed by Poly(ionic liquid)s

作　　者：王蔓 王鑫 周静 高国华 WANG Man;WANG Xin;ZHOU Jing;GAO Guohua(Shanghai Key Laboratory of Green Chemistry and Chemical Processes,School of Chemistry and Molecular Engineering,East China Normal University,Shanghai 200062,China;College of Chemistry and Chemical Engineering,Qiannan Normal University for Nationalities,Duyun 558000,China)

机构地区：[1]华东师范大学化学与分子工程学院,上海市绿色化学与化工过程绿色化重点实验室,上海200062 [2]黔南民族师范学院化学化工学院,都匀558000

出　　处：《高等学校化学学报》2021年第12期3701-3708,共8页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21773068);国家重点研发计划项目(批准号:2017YFA0403102,2020YFA0710201);上海市重点学科建设项目(批准号:B409)资助.

摘　　要：通过N-乙烯基咪唑鎓离子液体、丙烯酸钠(NaAA)和交联剂二乙烯基苯(DVB)或1-乙烯基-3-三乙二醇基咪唑溴盐{[(EG)_(3)-DVIm]Br_(2)}自由基聚合合成了一系列含羧酸根的聚离子液体.将所合成的聚离子液体用于催化甲醇与碳酸乙烯酯(EC)酯交换反应制备碳酸二甲酯(DMC).研究结果表明,在甲醇和EC混合溶剂中具有最大溶胀度的聚离子液体催化剂poly[VOIm-AA-DVIm]活性最高.在优化反应条件[120℃,6 h,1.0%(摩尔分数)催化剂用量,n(甲醇)/n(EC)=10∶1]下,DMC收率为76.6%,选择性为90.1%,达到了与均相催化剂1-丁基-3-甲基咪唑醋酸盐([BMIm]OAc)相当的活性.A series of poly(ionic liquid)s containing carboxylate anions was synthesized by free radical copo⁃lymerization of N-vinylimidazolium ionic liquids,sodium acrylate and crosslinker divinylbenzene(DVB)or 1,8-triethylene glycoldiyl-3,3′-divinylimidazolium bromide{[(EG)_(3)-DVIm]Br_(2)}.These poly(ionic liquid)s were characterized by nuclear magnetic resonance(NMR)spectroscopy,Fourier transform infrared spectro⁃scopy(FTIR)and thermogravimetric analysis(TGA).The swelling properties of poly(ionic liquid)s in metha⁃nol-EC mixed solvents could be regulated by cross-linking agents and 3-alkyl-substituents on imidazolium.These poly(ionic liquid)s were used to catalyze the transesterification of methanol and ethylene carbonate(EC)to synthesize dimethyl carbonate(DMC).The catalytic activity of poly(ionic liquid)s increased with the increase of swelling ratio.And poly[VOIm-AA-DVIm],which had the highest swelling ability(Q=25.9)in the mixed solvent of methanol and EC,had the highest catalytic activity.The effects of temperature,reaction time,amount of catalyst and molar ratio of methanol to EC on the transesterification process over the poly[VOIm-AA-DVIm]were investigated and discussed,respectively.Under the optimized reaction conditions[120℃,6 h,1.0%catalyst(molar fraction,based on carboxylate),n(methanol)n(/EC)=10∶1],the yield of DMC was 76.6%and the selectivity was 90.1%.The catalytic activity was comparable to that of the homoge⁃neous catalyst 1-butyl-3-methylimidazole acetate([BMIm]OAc).

关 键 词：聚离子液体 溶胀 酯交换反应 甲醇 碳酸二甲酯 

分 类 号：O643[理学—物理化学]