Chemistry Reference
In-Depth Information
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7.17.9 Poly(arylene ether)s and Poly(arylene ether ketone)s
High-performance polymeric material are poly(arylene ether)s and poly(arylene ether ketone)s. They
can be used as structural resins because in composite fabrications they offer an attractive combination
of chemical, mechanical, and physical properties.
Commercial poly(ether ketone)s that are also poly(arylene ether)s are formed from diacid chloride
by the Friedel-Craft reaction [
234
].
O
O
O
n
+
n
Cl
Cl
O
n
O
O
Similar polyketones form from dicarboxylic acids rather than dicarboxylic acid chlorides, when
P
2
O
5
—methanesulfonic acid is used as a catalyst [
235
]. All these materials form a group of tough,
high melting resins.
Some current preparations of poly(arylene ether)s are carried out by nucleophilic displacements of
activated aromatic dihalides or dinitro groups by alkali metal bisphenates. The reactions take place in
polar aprotic solvents. The glass transition temperatures, tensile strengths, and tensile moduli of these
materials tend to increase when heterocyclic units are incorporated into the backbones. Poly(arylene
ether)s containing imide [
236
], phenylquinoxaline [
237
-
239
], imidazoles [
240
], pyrazoles [
241
],
1,3,4-oxadiazoles [
240
], benzoxazoles [
240
], and benzimidazoles [
240
] groups were prepared.
