Dielectric dispersion of alternating copolymers of maleic acid.
Dielectric dispersions of three kinds of copolymers of maleic acid, poly (maleic acid-co-methyl vinyl ether) (PMAMVE), poly(maleic add-co-ethyl vinyl ether) (PMAEVE) and poly (maleic acid-co-styrene) (PMAST), were measured by use of a pseudorandom noise dielectric spectrometer. A large dielectric increment was observed in the low frequency region (10-20 Hz), and was explained in terms of our theory of ion fluctuation. When these copolymers were neutralized with mixtures of NaOH and Ca(OH)2 by changing their ratio, enhancement of the static dielectric increment was observed in the intermediate ratios of both ion species. This phenomenon was analyzed by modifying our. theory of ion fluctuation to the case of alternating copolymers. Quantitative agreement with experimental results was obtained by using values of parameters representing binding energies and mutual repulsion, which are chosen to fit the calculated degree of ion binding to the experimental data on activities of Na+ and Ca2+ ions. At large fractions of divalent ions, the increment, relaxation time and specific viscosity were found to decrease sharply due to chelation by divalent ions.
Minakata
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Department of Physics, Hamamatsu University School of Medicine, Hamamatsu, 431-31, Japan.
Shimizu
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Nakamura
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Wada
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