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 (H

2

SO

4

) or trifluoromethanesulfonic acid (CF

3

SO

3

H). 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-SO

3

H

]

HSO

4

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 condi

tions 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 4.12×10

7

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.