Handbook of Solvents - George Wypych - ChemTech - Ventech!

834 Maw-Ling Wang
substitution, such as 10%RS, 20%RS and 49%RS, to analyze the lipophilicity of the polymer
support. The order of the lipophilicity was 10%RS > 20%RS> 49%RS, which is the
same as the order of swelling. However, a maximum value of the apparent rate constant was
obtained for using a 20%RS pellet catalyst among the three kinds of ring substitution polymer
pellet. Therefore, it is concluded that the lipophilicity of the polymer cannot be too
large to enhance the reaction rate. This is due to the fact that the ion exchange rate is retarded
to lower the reaction rate because of using a high lipophilic polymer support. It is
concluded that the lipophilicity and the hydrophilicity highly influence the reactivity in
triphase catalysis.
For a two-phase PTC, it is recognized that the polarity of the organic solvent affects
the reaction rate. In general, the reaction rate increases with the augmentation of the polarity
of the solvents. Table 13.3.28 shows the effects of the organic solvents on the apparent rate
constant, k o,app and k a,app. 136 A higher value of the apparent rate constant was obtained using
solvent of high polarity. This result is consistent with the swelling and the imbibed compositions
that are given in Table 13.3.29. 136
Table 13.3.27. Compositions of the imbibed solvents and swelling volume of the
triphase catalyst pellet with various polymer structures
Triphase catalyst Conditions
microporous 2%
microporous 6%
microporous 10%
macroporous 2%
macroporous 6%
macroporous 10%
ClC 6H 5
H 2O/ClC 6H 5
2.8M NaOCH 2CF 3/ClC 6H 5
ClC 6H 5
H 2O/ClC 6H 5
2.8M NaOCH 2CF 3/ClC 6H 5
ClC 6H 5
H 2O/ClC 6H 5
2.8M NaOCH 2CF 3/ClC 6H 5
ClC 6H 5
H 2O/ClC 6H 5
2.8M NaOCH 2CF 3/ClC 6H 5
ClC 6H 5
H 2O/ClC 6H 5
2.8M NaOCH 2CF 3/ClC 6H 5
ClC 6H 5
H 2O/ClC 6H 5
2.8M NaOCH 2CF 3/ClC 6H 5
ClC6H5
g
1.31
1.23
1.92
1.19
1.17
1.90
1.06
0.96
1.40
1.28
1.33
2.29
1.54
1.25
2.2
0.76
1.05
1.28
H2O
g
NaOCH2CF3, g
(calcd value, g)
0.33
0.67 0.40 (0.29)
0.62
0.50 0.60 (0.22)
0.29
0.50 0.19 (0.22)
0.73
0.50 0.34 (0.22)
0.82
0.59 0.42 (0.25)
0.63
0.38 0.17 (0.16)
Swelling
volume ratio
Data obtained from Wang and Wu; 136 50 mL of chlorobenzene, 20 mL of water, 0.059 mole of (NPCl 2) 3, 0.7 meq of
catalyst was used, 20 o C
2.4
2.7
3.6
2.2
2.8
3.4
2.0
2.1
2.9
3.1
3.8
2.5
3.1
3.8
2.7
2.6