Characterization of high-performance polymer blends

Blending of polymers, a method used to engineer materials to provide specific properties, has been extended to high performance materials being developed for composite applications in the aerospace industry. The high performance requirements of such blends demand a complete understanding of the chemistry and morphology as a function of end-use temperatures. Multidisciplinary protocols for characterization of blends include microscopy, infrared and thermal analysis. The major issues involved in such a study of polymer blends will be described. Recently the Hoechst Celanese polybenzimidazole, [poly-2,2′(m-phenylene)-5,5′ bibenzimidazole], PBI, and the General Electric aromatic polyether imide [poly(2,2′-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane-m-phenylenediimine], Ultem 1000, which are being evaluated for aerospace applications, were found to form miscible blends. The large parts are being fabricated from fibers spun from concentrated solutions (dopes).