Crystal Structure of Novel Polyamides with Long Diacid Segment: Polyamides 2 16, 4 16, 6 16, 8 16, 10 16, and 12 16

摘要

The morphologies of a series of novel polyamides with a long diacid segment were carefully studied using transmission electron microscopy (TEM), while their crystal structure was investigated using both TEM and wide-angle X-ray diffraction (WAXD). It was seen that the solution-grown crystals of all polyamides in this work were lath-like and crystallized as chain-folded, hydrogen-bonded sheet lamellae from 1,4-butanediol. The electron diffraction of these samples reveals that two crystalline phases are present including both α_p and β_p in all polyamides under consideration except for polyamide 2 16, which only consists of one crystal form, α_p. In addition, sedimented mats of these polyamide crystals and stretched film samples were examined by WAXD. The unit cell parameters for these crystals were calculated thereinafter.