
74 HIGH PERFORMANCE POLYMERS
OCH
3
O
CH
2
P(OC
2
H
5
)
2
O
(C
2
H
5
O)
2
PH
2
C
O
S
BrC
H
O
+
S
Br
OCH
3
O
Br
S
CH
3
MgCl
S
OCH
3
O
S
Figure 3.6
Grignard
metathesis polymerization [15].
R
R
R
R
R
R
R
R
Br
Br
R
R
+ e
-
- Br
-
R
R
R= H or Br
Figure 3.7 Synthesis of poly(
p
-phenylenevinylene)
by electropolymerization.
Co-electrolysis of different 1,4-bis-(halomethyl)-
arenes results in random copolymers [17]. Carboxyl
functionalities yield water-soluble polymer salts.
3.2.6 Knoevenagel
Polycondensation
Typically, in the Knoevenagel polycondensa-
tion, a terephthalic aldehyde is condensed with
a bis-(cyanomethyl)-benzene compound. Since two
CH
2
CH
2
CN
NC
R
R
C
C
R
R
HH
OO
+
CN
NC
R
R
R
R
Figure 3.8 Synthesis of PPV with pendant cyano
groups ...