Abstract
Experimentally observed a +-type Hv and a circular-type Vv scattering patterns from small-angle light scattering (SALS) measurement indicated a random assembly of sheaf-like or rod-like superstructure for poly(trimethylene terephthalate) (PTT) under cold-crystallization. The long period and crystallite thickness of cold-crystallized PTT have been determined by small-angle X-ray scattering (SAXS). The crystallite thickness is very small, ca 2nm, which is close to the c-axis (chain axis) of unit cell in PTT crystal, 18.64Å. The intermolecular crystallization may be viewed as a behavior of physical gelation. The liquid–solid transition in PTT crystallization from glassy state through the gel point has been investigated by dynamic mechanical experiments. The power law relaxation modulus, E(t)=St−Δ identifies the gel point, and small frequency window is sufficient to determine the relaxation exponent, Δ. The gel point occurs at the very early stage of crystallization, in which the relative degree of crystallinity is found to be about 2–3%. The Δ value is ca 0.52, which is independent of crystallization temperature.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.