SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2019, Vol. 27 ›› Issue (10): 2455-2466.DOI: 10.1016/j.cjche.2019.01.039

• • 上一篇    下一篇

Porous polymer microsphere functionalized with benzimidazolium based ionic liquids as effective solid catalysts for esterification

Xiaomei Ling, Yiwei Xie, Xiaocheng Lin, Ling Li, Ting Qiu   

  1. School of Chemical Engineering, Fuzhou University, Fuzhou 350116, Fujian, China
  • 收稿日期:2018-04-11 修回日期:2019-01-21 出版日期:2019-10-28 发布日期:2020-01-17
  • 通讯作者: Ting Qiu
  • 基金资助:
    The National Natural Science Foundation of China (21576053, 91534106) and the Natural Science Foundation of Fujian Province (2016J01689).

Porous polymer microsphere functionalized with benzimidazolium based ionic liquids as effective solid catalysts for esterification

Xiaomei Ling, Yiwei Xie, Xiaocheng Lin, Ling Li, Ting Qiu   

  1. School of Chemical Engineering, Fuzhou University, Fuzhou 350116, Fujian, China
  • Received:2018-04-11 Revised:2019-01-21 Online:2019-10-28 Published:2020-01-17
  • Contact: Ting Qiu
  • Supported by:
    The National Natural Science Foundation of China (21576053, 91534106) and the Natural Science Foundation of Fujian Province (2016J01689).

摘要: To prepare polymer supported ionic liquids (PSILs) as effective catalysts for esterification, the free radical suspension copolymerization of vinylbenzyl chloride (VBC, monomer), styrene (St, monomer) and divinylbenzene (DVB, crosslinker) with the addition of n-heptane (porogen) was carried out for the fabrication of the porous polymer (PVD) microsphere as support, followed by the immobilization of sulfonic acid-functionalized ionic liquids by the successive treatment of benzimidazole (BIm), 1,3-propane sultone and sulfuric acid (H2SO4) or trifluoromethanesulfonic acid (CF3SO3H). The effects of the compositions of DVB and n-heptane on the internal structure of the polymer supports were investigated, and it was found that the support with 40 wt% DVB and 60 wt% n-heptane (with relative to the monomer) could endow the final PSILs with the relatively optimal catalytic performance. The preliminary experiment in the batch reactor indicated that PSILs herein exhibited higher catalytic activities than commercial Amberlyst 46 resin for the esterification of propanoic acid (PROAc) with n-propanol (PROOH). Consequently, the optimal PSILs catalyst, PVD-[Bim-SO3H]HSO4, was selected for further study in the batch reactive distillation column because of low cost and its ease of preparation. The yield of propyl ropionate (PROPRO) could reach up to 97.78% at the optimized conditions of PROOH/PROAc molar ratio (2:1) and catalyst dosage (2.0 wt%). The investigation of the reaction kinetic manifested that the calculated results of second order pseudo-homogeneous kinetic model were in good agreement with experimental values. The pre-exponential factor and activation energy were 4.12×107 L·mol-1·min-1 and 60.57 kJ·mol-1, respectively. It is worth noting that the PSILs catalyst could be simply recovered and reused with relatively satisfactory decrease in the catalytic activity, which made it an environmental friendly and promising catalyst in the industrial application.

关键词: Supported ionic liquids, Porous polymer microsphere, Copolymerization, Esterification, Reactive distillation

Abstract: To prepare polymer supported ionic liquids (PSILs) as effective catalysts for esterification, the free radical suspension copolymerization of vinylbenzyl chloride (VBC, monomer), styrene (St, monomer) and divinylbenzene (DVB, crosslinker) with the addition of n-heptane (porogen) was carried out for the fabrication of the porous polymer (PVD) microsphere as support, followed by the immobilization of sulfonic acid-functionalized ionic liquids by the successive treatment of benzimidazole (BIm), 1,3-propane sultone and sulfuric acid (H2SO4) or trifluoromethanesulfonic acid (CF3SO3H). The effects of the compositions of DVB and n-heptane on the internal structure of the polymer supports were investigated, and it was found that the support with 40 wt% DVB and 60 wt% n-heptane (with relative to the monomer) could endow the final PSILs with the relatively optimal catalytic performance. The preliminary experiment in the batch reactor indicated that PSILs herein exhibited higher catalytic activities than commercial Amberlyst 46 resin for the esterification of propanoic acid (PROAc) with n-propanol (PROOH). Consequently, the optimal PSILs catalyst, PVD-[Bim-SO3H]HSO4, was selected for further study in the batch reactive distillation column because of low cost and its ease of preparation. The yield of propyl ropionate (PROPRO) could reach up to 97.78% at the optimized conditions of PROOH/PROAc molar ratio (2:1) and catalyst dosage (2.0 wt%). The investigation of the reaction kinetic manifested that the calculated results of second order pseudo-homogeneous kinetic model were in good agreement with experimental values. The pre-exponential factor and activation energy were 4.12×107 L·mol-1·min-1 and 60.57 kJ·mol-1, respectively. It is worth noting that the PSILs catalyst could be simply recovered and reused with relatively satisfactory decrease in the catalytic activity, which made it an environmental friendly and promising catalyst in the industrial application.

Key words: Supported ionic liquids, Porous polymer microsphere, Copolymerization, Esterification, Reactive distillation