Terephthalamide-nylon single crystals isolated from dilute solutions of hexafluoro-2,2-propandiol

Terephthalamide nylons with two to five carbon atoms in the aliphatic portion of the chain have been crystallized from aqueous solutions of hexafluoro-2,2-propandiol. The 3T and 4T nylons in particular form rodlike crystals. Indications are that these are bundles of cylindrical structures about 50 nm in diameter. Electron diffraction shows the symmetry to be C_2v. Films of the nylons were drawn with great difficulty. The x-ray diffraction on the films is consistent with a monoclinic structure, though the crystal structure could not be positively established. There is some evidence for a polymer chain alignment perpendicular to the long axis of the rods.