Polymer and Materials Science
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Processable, thermally stable aramides were prepared from multi-ring flexible aromatic diamines and diacids by direct polycondensation at 100°C with the triphenylphosphitel pyridine system in N-methyl-2-pyrrolidone/LiCl. The monomers used are characterized by the presence of all m-, all p-, or m, p-oriented aryloxy groups and, in some cases, by ring substitution with methyl or phenyl groups. The poly(etheramide)s (PEAs) prepared have moderate polymerization degrees (ηinh 0.55-2.74) and their solubility in organic solvents depends on their structural features. Differential scanning calorimetry (DSC), and wide-angle X-ray diffraction analysis revealed a partial crystallinity for “as-polymerized” PEAs derived from p-oriented monomers. The thermal behavior was investigated by DSC, dynamic-mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The glass transition temperatures, as determined by DSC and DMTA, are spread over a wide temperature range, 140-274°C, and depend on the number of aryloxy groups and their catenation as well as on the presence of ring substituents. The TGA results indicate thermal stability (10% weight loss) up to 490°C. Tough, flexible films are produced by solution casting or by compression molding in the case of amorphous PEAs.
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