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JIAHUI XIE et al.
the washing solution was quite similar to the reaction
С Kα1_2
mixture. The product content was even higher due to
the bigger molecule size, which would be adsorbed in
the polymer more strongly. Combined with the little
catalyst amount, the absorption attached little impor-
tance to the yield. The recycled activities showed that
the polymer owned high stability with the yield
remained after being recycled for six times. For fresh
catalyst, the intermediate yield of 85% was obtained
after 2 min, while the yield of 84% was obtained for the
recycled polymer. The result further confirmed the
high stability of the polymer. The polymer owned the
hypercrosslinked structures with the bulky cations
embedded in framework, which effectively avoided the
active sites releasing and pore blocking. High BET
surface area and large pore volume benefited the mass
transfer and avoided the carbon deposition. The recy-
cled polymer still showed the similar BET surface area
of 546 m2/g to the fresh catalyst. The FT-IR spectrum
also showed the no changes, which indicated that the
structure was well kept during the catalytic process.
10 μm
Fig. 5. The EDX analysis of Cl element in ionic polymer
from n-butanol.
4. CONCLUSIONS
was soluble in the reaction system, which added the
separation difficulty.
The novel porous ionic polymer was synthesized
from the simple one-pot polymerization and quaterni-
zation of 4-vinyl pyridine and 4-chloromethyl styrene.
The solvents were very important for the polymer
structures, which acted as the porogen. The polymer
from n-butanol owned high BET surface of 555.6 m2/g
and large pore volume, which provided the easily
accessible active sites to reactants. The ionic polymer
showed even higher activity for aza-Michael additions
than the IL. High activity, high BET surface area and
high stability were the key properties of the ionic poly-
mer, which combined the advantages of solid catalysts
and IL. The simple one-pot synthetic route and high
IL loading amount made the polymer hold great
potential in green chemical processes.
The reaction between diisopropylamine and
methyl acrylate with high steric hindrance was also
investigated. The polymers also showed even higher
activities than IL. The polymer from butanol showed
the yield of 99% after 7 min. The reaction time was
longer due to the higher steric hindrance. The polymer
from isopropanol also gave the high yield of 99% after
10 min. The mesoporous structure was quite suitable
for big molecules and diisopropylamine molecules
could easily enter into the mesopores and interact with
the active sites. As a result, the ionic polymer from iso-
propanol showed highest yield even though the BET
surface area was low. The polymer from acetone
showed lowest activity due to the low BET surface
area. The bulky reactant molecules could hardly inter-
act with the active sites inside and the reaction was
carried out only around the accessible external sur-
face, which accounted for the low activities.
ACKNOWLEDGMENTS
The work was supported by Zhejiang Xinmiao tal-
ent projects (grant no. 2016R428007).
For IL, the reaction was carried out homoge-
nously, but the yield was still lower than the heteroge-
neous polymer. The polymer with organic polymeric
framework showed high affinity with reactants, which
caused the enrichment effect of reactants.
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KINETICS AND CATALYSIS
Vol. 58
No. 3
2017