Crystal and Molecular Simulation of High-Performance Polymers

Single-crystal X-ray analyses of oligomeric models for high-performance aromatic polymers, interfaced to computer-based molecular modeling and diffraction simulation, have enabled the determination of a range of previously unknown polymer crystal structures from X-ray powder data. Materials which have been successfully analyzed using this approach include aromatic polyesters, polyetherketones, polythioetherketones, polyphenylenes, and polycarboranes. Pure macrocyclic homologues of noncrystalline polyethersulfones afford high-quality single crystals even at very large ring sizes and have provided the first examples of a “protein crystallographic” approach to the structures of conventionally amorphous synthetic polymers. “ What Linus did [in discovering the α-helix] was to insist that, from his data on the crystal structures of simple molecules, he could extrapolate. For example that the peptide bond had to be planar. ” (H. F. Judson, The Eighth Day of Creation; Simon and Schuster: New York, 1979).