
7: POLY(ARYLENE ETHER SULFONE)S 181
Figure 7.4 Synthesis of 3,3
,5,5
-tetra(4
-meth-
oxyphenyl)-4,4
-difluorodiphenyl sulfone [22].
S
O
O
F
F
OCH
3
OCH
3
CH
3
O
CH
3
O
B(OH)
2
CH
3
O
S
O
O
F
F
S
O
O
F
F
Br Br
Br Br
before crosslinking, the membranes can be fabricated
by solution casting methods.
7.1.7 3,3
,5,5
-Tetra(4
-methoxy-
phenyl)-4,4
-difluorodiphenyl
sulfone
Monomers with pendant methoxyphenyl groups
can be synthesized by the bromination of bis(4-
fluorophenyl)sulfone, followed by a Suzuki coupling
with 4-methoxybenzeneboronic acid [22]. The synthe-
sisisshowninFigure 7.4.
The methoxy group is a protective group and can
be converted into a hydroxyl group after polyconden-
sation. ...