1H-NMR studies on water in methacrylate hydrogels. I

Autor: Minoru Todoki, Kazuhiko Ishikiriyama, Atsuko Yamada-Nosaka, Hiroshi Tanzawa
Rok vydání: 1990
Předmět:
Zdroj: Journal of Applied Polymer Science. 39:2443-2452
ISSN: 1097-4628
0021-8995
Popis: Properties of water in the wet membranes of a random copolymer of methyl methacrylate and methoxy poly(ethylene glycol)–monomethacrylate P(MMA-co-M100G) and of a graft copolymer of vinyl chloride and methoxy poly(ethylene glycol)–monomethacrylate P(VC-g-M100G) membranes were studied by proton NMR spectroscopy. Both polymers contain flexible polyoxyethylene side chains. Temperature and frequency dependences of relaxation times, changes of signal intensity of water protons on freezing and thawing, and saturation transfer were measured for both copolymers. These experimental results revealed that most of the bound water in these copolymers does not exist in a rigid state as suggested for the other hydrogels. The introduction of flexible hydrophilic side chains resulted in high mobility of the water molecules bound to the side chains (the apparent correlation time Tc ∼ 10−10 s). For the graft copolymer P(VC-g-M100G), hydrophilic polyoxyethylene side chains are contiguous to each other. Because of the interaction between the side chains, the mobility became more complex than that for the random copolymer P(MMA-co-M100G). The difference in the mode of mobility of water on the membrane surface may be related to the difference of the membrane characteristics of these copolymers.
Databáze: OpenAIRE
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