CPS K 221 Model of proton longitudinal magnetic relaxation in hydrated crosslinked poly(methacrylic acid) |
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Authors: | K Erdmann A Gutsze |
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Institution: | (1) Present address: Institute of Chemistry, Nicholas Copernicus University, Toru, Poland;(2) Institute of Physics, Nicholas Copernicus University, Toru, Poland |
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Abstract: | Proton longitudinal magnetic relaxation time (T1) measurements have been made at 30 MHz over a wide range of temperature for crosslinked poly(methacrylic acid), PMA, hydrated with H2O as well as with D2O. From the point of view of nuclear magnetic relaxation, PMA hydrogel is a multiregion system in which three proton regions (a, b, c) can be distinguished. Region a is regarded as to be formed by the nonexchangeable polymer protons, region b by the protons of -COOH · H2O combinations, and region c by the protons of remaining water molecules. Cross relaxation between polymer and water protons and a log normal distribution of correlation times have been assumed to take place. Temperature dependences of the T1 time for the particular regions have been determined, from which the distribution width parameter, the second moment and the intramolecular proton-proton distance for sorbed water have been calculated. |
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Keywords: | Poly (methacrylic acid) ion exchange resin hydration proton magneticrelaxation |
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