Cg. Herbert et al., PREPARATION OF POLY(ARYLENE ETHER PYRIMIDINE)S BY AROMATIC NUCLEOPHILIC-SUBSTITUTION REACTIONS, Macromolecules, 29(24), 1996, pp. 7709-7716
As part of a continuing effort to prepare novel thermally stable high-
performance polymers, poly(arylene ether pyrimidine)s have been prepar
ed with 4,6-bis(4-(trimethylsiloxy)phenyl)pyrimidine and a series of a
ctivated bis(aryl fluoride)s using a catalytic amount of cesium fluori
de in diphenyl sulfone. These polymers exhibited good thermal stabilit
y in both air and helium atmospheres with 10% weight losses in the ran
ge 480-540 degrees C. Moderate to high inherent viscosities (eta(inh):
0.40-0.92 dL/g) were recorded, and clear pale yellow flexible fingern
ail creasable films were solution cast from these samples. A polymer i
n this series containing a phenylphosphine oxide linkage exhibited goo
d thin film tensile properties and resistance to oxygen plasma. Model
reactions with 4,6-bis(4-fluorophenyl)pyrimidine and p-cresol along wi
th studies of this compound's F-19 NMR shift values indicated sufficie
nt capacity of the pyrimidine ring to activate aryl fluorides toward p
olymerization with bis(phenol)s. The pyrimidine bis(aryl fluoride) mon
omer was used to prepare a series of polymers with selected bis(phenol
)s by potassium carbonate-mediated aromatic nucleophilic substitution
reactions. One example containing the fluorene moiety exhibited a high
inherent viscosity (eta(inh): 0.80 dL/g); however, only brittle films
could be cast from polymers prepared by this approach.