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Gelation of a new hydrogel system of atactic ‐poly(vinyl alcohol)/NaCl/H 2 O
Author(s) -
Dai Lixing,
Ukai Kohshuke,
Shaheen Sharif Mohammad,
Yamaura Kazuo
Publication year - 2002
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.951
Subject(s) - self healing hydrogels , vinyl alcohol , syneresis , aqueous solution , melting point , chemical engineering , polymer chemistry , melting temperature , materials science , freezing point , polyvinyl alcohol , chemistry , nuclear chemistry , polymer , composite material , organic chemistry , physics , engineering , thermodynamics
Abstract a ‐PVA/NaCl/H 2 O hydrogels have been prepared by gelation of aqueous atactic ‐poly(vinyl alcohol) ( a ‐PVA) solutions in the presence of NaCl. The gelling temperature, melting temperature and the preservation of water of the hydrogels have been measured. The effect of the addition of NaCl to the hydrogels on gelling temperature and melting temperature is marked when the NaCl concentration is over a certain value. High NaCl concentration favours high‐melting‐point hydrogels. When the NaCl concentration is high enough (such as 11%), high‐melting‐point and white turbid opaque a ‐PVA/NaCl/H 2 O hydrogels can be prepared, regardless of the PVA concentration. Similarly, the low gelling temperature of a ‐PVA/NaCl/H 2 O solutions comes from low NaCl concentration, while high gelling temperature ranges from 50 to 70 °C when the NaCl concentration is 11%. In appearance, the types of syneresis of a ‐PVA/NaCl/H 2 O are χ‐type or a mixture of χ‐ and n ‐types; water release of the hydrogels is slowed down by the addition of NaCl. © 2002 Society of Chemical Industry