
8: POLY(ARYLENE ETHER NITRILE)S 213
Figure 8.5 Monomers for
Friedel-Crafts
polymer-
ization [29].
2,6-Diphenoxybenzonitrile
CN
O
O
Benzofuro[2,3-b]benzofuran-2,9-dicarbonyl dichloride
OO
CC
OO
ClCl
1,4-Bis(p-phenoxybenzoyl)benzene
CC
OO
OO
1,3-Bis(p-phenoxybenzoyl)benzene
CC
OO
OO
OO
OO
1,1′-Bis(p-phenoxybezoyl)[2.2]Metacyclophane
polymerization reaction is carried out at a subambient
temperature so that the reaction proceeds at a con-
trollable rate [32,33]. The materials are useful as gas
separation membranes.
8.3 Properties
The family of PEN polymers exhibits a good radi-
ation resistance and low flammability and toxic gas
emission. The cyano group, because of its polarity ...