Manipulation of nylon-6 crystal structures with its alpha-cyclodextrin inclusion complex

作者：Wei M; Davis W; Urban B; Song YQ; Porbeni FE; Wang XW; White JL; Balik CM; Rusa CC; Fox J; Tonelli AE^*

来源：Macromolecules, 2002, 35(21): 8039-8044.

DOI：10.1021/ma020765m

We successfully formed an inclusion complex between nylon-6 and a-cyclodextrin and attempted to use the formation and subsequent disassociation of the nylon-6/alpha-cyclodextrin inclusion complex to manipulate the polymorphic crystal structures, crystallinity, and orientation of nylon-6. Formation of the inclusion complex was verified by Fourier transform infrared (FTIR) spectroscopy, wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), and CP/MAS C-13 NMR. After obtaining the inclusion complex of nylon-6 and a-cyclodextrin, the sample was treated in an acid environment to remove the host a-cyclodextrin and coalesce the nylon-6 guest polymer. Examination of as-received and IC coalesced nylon-6 samples showed that the a-form crystalline phase of nylon-6 is the dominant component in the coalesced sample. X-ray diffraction patterns demonstrate that the gamma-form is significantly suppressed in the coalesced sample. Along with the change in crystal form, an increase in crystallinity of similar to80% was revealed by DSC, and elevated melting and crystallization temperatures were also observed for the coalesced nylon-6 sample. FTIR spectroscopy revealed a significant degree of orientaion for the nylon-6 chains coalesced from their alpha-cyclodextrin inclusion complex crystals. Thermogravimetric analysis indicated that nylon-6 has an similar to30 degreesC higher thermal degradation temperature after modification by threading into and being extracted from its a-cyclodextrin inclusion complex.

• 出版日期2002-10-8