Segmented copo lymer systems composed of an amorphous g1assy
engineering polymer as one segment and a potentially anisotropic
polyester as the second segment were synthesized and investigated.
The engineering thermoplastic segment was based on various all
aromatic poly(arylene ether sulfooes) derived from the nucleophilic
aromatic substitution reaction between hydroquinone, biphenol, and
dichlorodiphenylsulfone. This reaction was conducted in the presence
of potassium carbonate and anhydrous aprotic dipolar solvents.
Poly(biphenol terephthalate) and poly(oxybenzoate) were synthesized in
situ as the second, potentially anisotropic, sem;crystalline segment.
These segmented copolymers were synthesized either by solution t
interfacial, or melt acidolysis techniques. The melt acidolysis
technique was used to synthesize the segmented copolymers with high
poly(arylate) contents. The morphology of the copolymers was found to
be totally amorphous for those capolymers with low 1eve1s of the
poly(arylates). They were semicrystalline when the poly(arylate) contents were increased beyond a critical value of about 15 weight
percent. Differential scanning calorimetry, optical microscopy, and
wide angle X-ray scattering were used to probe the copolymer
morphology. The chemical structures of the segmented copolymers were
studied through the use of Fourier transform infrared spectroscopy and
nuclear magnetic resonance spectroscopy (both 1H and 13C). As the
weight percentage of the poly(arylate) was increased, a very
significant improvement in the solvent resistance was noted. Evidence
of anisotropy and liquid crystallinity in the copolymers was provided
by optical microscopy, differential scanning calorimetry, and wide
angle X-ray scattering.
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