Effect of stereosequences on crystallinity and properties of zone-drawn poly(vinyl alcohol) microfibrils

Won Seok Lyoo, Joon Ho Kim, Kang Koo, Joon Seok Lee, Sam Soo Kim, Won Sik Yoon, Byung Chul Ji, Ick Chan Kwon, Chul Joo Lee

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)

Abstract

To effectively orient the molecular chains of novel syndiotactic poly(vinyl alcohol) (PVA) microfibrillar fiber (PVA fibril), a high-temperature zone-drawing method was adopted. The PVA fibrils were directly prepared from the saponification and in situ fibrillation without a spinning procedure. The maximum draw ratio of the PVA fibril increased with a decrease in the syndiotactic diad (r-diad) content, indicating that the deformability of PVA molecules was lowered in higher syndiotactic PVA. Degree of crystal orientations up to 0.990 were achieved by stretching the PVA fibril with the r-diad content of 65.1% and the original degree of crystal orientation of 0.902 at 250°C close to its crystal melting temperature (Tm). When the same draw ratio was applied to the fibrils, a higher crystal orientation was achieved for the fibrils having higher syndiotacticity. Wide-angle X-ray data show that the longitudinal crystal sizes of drawn PVA fibrils were larger in higher syndiotacticities. The degree of crystal orientation, crystallinity, Tm, longitudinal crystal size, and tensile strength of the maximum drawn PVA fibril with a r-diad content of 65.1% were 0.99, 0.97, 279°C, 187 Å, and 4.66 N/tex, respectively.

Original languageEnglish
Pages (from-to)1263-1271
Number of pages9
JournalJournal of Polymer Science, Part B: Polymer Physics
Volume39
Issue number12
DOIs
Publication statusPublished - 2001 Jun 15

Keywords

  • Crystal orientation
  • High-temperature zone drawing
  • Maximum draw ratio
  • PVA fibril
  • Syndiotacticity

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Polymers and Plastics
  • Materials Chemistry

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