Morphology and Structure of Chain-Folded Lamellar Crystals of Nylons 2 22, 4 22, 6 22, 8 22, 10 22, and 12 22

Abstract

Chain-folded lamellar crystals of nylons 2 22, 4 22, 6 22, 8 22, 10 22, and 12 22 are grown from 1,4-butanediol solution, and their morphology and crystalline structure are investigated by using transmission electron microscopy (TEM) and wide-angle X-ray diffraction (WAXD). It is found that nylons 4 22, 6 22, 8 22, 10 22, and 12 22 have a similar crystalline structure. All of them crystallize into the triclinic structure of the nylon 6 6 αp phase, and their unit cell parameters are also similar to those of nylon 6 6. On the other hand, nylon 2 22 is special in the crystalline structure compared with other ones. Although nylon 2 22 also adopts the triclinic αp phase, its characteristic signals of diffraction are different from other nylons of this series and nylon 6 6, but similar to those of the nylon 2 Y family. Furthermore, its parameters of the unit cell calculated from the experimental data come to the same conclusion.