Details

Autor(en) / Beteiligte

• Asano, Atsushi
• Koyama, Hiroyuki
• Suzuki, Akihiro

Titel

Crystal growth of PPS nanofibers during annealing studied by solid‐state 13 C CPMAS NMR

Ist Teil von

• Journal of applied polymer science, 2022-03, Vol.139 (10)

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• Abstract Initial crystalline phase growth property for poly( p ‐phenylene sulfide) (PPS) nanofibers during annealing are studied by means of the 13 C high‐resolution solid‐state cross‐polarization/magic‐angle‐spinning NMR ( 13 C CPMAS NMR) with spectral editing procedure using the difference in 1 H spin‐lattice relaxation time in the rotating frame ( T 1ρ H ) between the crystalline and non‐crystalline phases. The PPS nanofibers are prepared by drawing the solid microfibers melted by a high‐power carbon dioxide (CO 2 ) laser with supersonic jet velocity of 300–600 ms −1 in a vacuum chamber (CLSD method). The crystallinity and molecular orientation of the pristine drawn PPS nanofibers increase with decrease of the chamber pressure ( p ch ). The growing process and the ordered chain packing of the crystalline phase during annealing depend on the initial chain orientation. The low pressures at p ch  = 30 and 10 kPa significantly relate to the initial nucleation growth of the PPS nanofibers. In the initial crystal growth of PPS nanofibers obtained at p ch  = 30 kPa for the low temperature annealing, the rearrangement of chains occurs, but for those at p ch  = 10 kPa the rearrangement does not occur. This is because the highly ordered chain alignments and packing are already achieved for PPS nanofibers obtained at p ch  = 10 kPa.