Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (12): 3701.doi: 10.7503/cjcu20210498

• Physical Chemistry • Previous Articles     Next Articles

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

WANG Man1, WANG Xin1, ZHOU Jing2(), GAO Guohua1()   

  1. 1.Shanghai Key Laboratory of Green Chemistry and Chemical Processes,School of Chemistry and Molecular Engineering,East China Normal University,Shanghai 200062,China
    2.College of Chemistry and Chemical Engineering,Qiannan Normal University for Nationalities,Duyun 558000,China
  • Received:2021-07-14 Online:2021-12-10 Published:2021-10-07
  • Contact: ZHOU Jing,GAO Guohua E-mail:qnsytaoer@163.com;ghgao@chem.ecnu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21773068);the National Key Research and Development Program of China(2017YFA0403102);the Shanghai Leading Academic Discipline Project, China(B409)

Abstract:

A series of poly(ionic liquid)s containing carboxylate anions was synthesized by free radical copolymerization of N-vinylimidazolium ionic liquids, sodium acrylate and crosslinker divinylbenzene(DVB) or 1,8-triethylene glycoldiyl-3,3′-divinylimidazolium bromide{[(EG)3-DVIm]Br2}. 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 methanol-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 homogeneous catalyst 1-butyl-3-methylimidazole acetate([BMIm]OAc).

Key words: Poly(ionic liquid), Swelling, Transesterification, Methanol, Dimethyl carbonate

CLC Number: 

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