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Effect of iodine absorption on the characteristics of syndiotacticity‐rich high molecular weight poly(vinyl alcohol) microfibril
Author(s) -
Ghim Han Do,
Kim Jae Pil,
Kwon Ick Chan,
Lee Chul Joo,
Lee Jinwon,
Kim Sam Soo,
Lee Sung Min,
Yoon Won Sik,
Lyoo Won Seok
Publication year - 2002
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.11551
Subject(s) - microfibril , vinyl alcohol , materials science , polymer chemistry , differential scanning calorimetry , tacticity , chemical engineering , iodine , composite material , chemistry , polymer , organic chemistry , cellulose , polymerization , physics , engineering , metallurgy , thermodynamics
Iodination of syndiotacticity‐rich high molecular weight poly(vinyl alcohol) (PVA) microfibril, which was obtained from the saponification of poly(vinyl pivalate) without a spinning procedure, was conducted before and after zone drawing at various conditions. The resulting PVA microfibrils were characterized by differential scanning calorimetry and scanning electron microscopy. Surface morphologies of these PVA microfibrils showed some differences between PVA microfibrils iodinated after and before drawing. Crude shapes of PVA microfibrils iodinated after drawing indicated that iodine decreased the structural regularity severely. On the other hand, PVA microfibrils iodinated before drawing showed relatively ordered surfaces. This was ascribed to the enhanced molecular ordering of PVA microfibrils due to zone drawing. Iodinated PVA microfibrils showed a decrease in the crystal melting temperature of about 100°C compared to the untreated sample. PVA microfibrils drawn after iodination showed a relatively higher crystal melting temperature than those of microfibrils iodinated after drawing. These results were considered as proof of the changes in the crystalline lattice of the PVA microfibrils by iodine absorption. Effects of the drawing temperature on the sublimation of iodine were also evaluated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1519–1524, 2003