Year-end Sale % OFF 
Abstract
Conformational conversion and molecular dynamics of the amorphous poly(ethylene terephthalate) (PET) annealed above Tg were investigated by 13C high-resolution solid-state NMR and differential scanning calorimetry (DSC). Rapid increase in the PET trans content and crystallinity were observed near the onset crystallization temperature (≅120°C). By comparing both changes in conformation and crystallinity during thermal annealing, we found that the trans conformer increases continuously while the degree of crystallinity levels off during the later stage of annealing. The 1H spin–lattice relaxation time in the rotating frame (T1ρH) correlates linearly with PET crystallinity but less well with the trans content. A three-domain model containing crystalline (all trans), constrained noncrystalline (trans rich) and amorphous (gauche rich) phases satisfactorily explains the relationship among the PET conformation, crystallinity and annealing conditions. This study complements the prior study of molecular motion by T1ρC and illustrates the importance of the trans conformer to induce PET crystallization.
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
