Having previously demonstrated the possibility of
synthesizing high molecular weight poly(ether imide)s with ortho-linked main-chain units from
bis(ether anhydride)s derived from catechol or
its derivatives, we now provide a preliminary assessment of the
properties of the polymers prepared
from the catechol bis(ether anhydride) and a variety of diamines.
The polymers have low color, are soluble
in a variety of solvents, and are thermally stable to temperatures in
excess of 470 °C. Glass transition
temperatures are comparable with or higher than that of the commercial
poly(ether imide) Ultem. Solvent-cast films have high modului and strengths. Extensions to break are
relatively low, except for the polymer
based on 4,4‘-bis(4-aminophenoxy)biphenyl, which has an
extension of 170%. All the polymers can be
drawn to produce materials with higher moduli and strengths and, in
most cases, higher extensions to
break. Thus the polymers can be processed from the melt or from
solution.
The primary quantum yields for formation of OH radicals in the photolysis of the monomer and dimer of formic, acetic, and propionic acid vapor at 222 nm have been determined at two temperatures for the first time. The absorption cross sections of the monomer and dimer of each acid were also determined at 222 nm. The quantum yield measurements were made by using a laser photolysis-resonance absorption technique and are relative to the quantum yield of OH from the photolysis of nitric acid, which was taken as unity. The OH quantum yields from the monomers were found to be the following: formic, 0.70-0.80; acetic, 0.55-0.70; propionic, 0.15-0.35. The quantum yields from the dimers were 0.15 for formic acid and near zero for the other acids. The differences in OH quantum yields for the monomer and dimer are interpreted in terms of the reaction pathway imposed by the structure of the dimer.
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