Counterion Effect on the Titration Behavior of Poly(itaconic acid)

DOI PDF 1 Citations 28 References Open Access
  • Muto Nobuhiko
    Department of Polymer Science, Faculty of Science, Hokkaido University

Search this article

Description

The effect of counterions on the titration behavior of poly(itaconic acid) (PIA) was studied by titrating PIA in aqueous solutions containing alkali metal salts and a tetramethylammonium salt at 25°C. The acidity of the primary carboxylic groups of PIA increases in the order (CH3)4N+<Li+<Na+<K+, whereas that of the secondary carboxylic groups increases with the decrease in the crystallographical radii of the counterions, in the order (CH3)4N+K+<Na+<Li+, in agreement with the results for ordinary polycarboxylic acids. The order K+>Na+>Li+ on the binding strength to the primary carboxylate groups in the first dissociation step is interpreted in terms of the radii of the hydrated cations; it can be ascribed to the stable ring structure of the monoanion of the itaconic acid residue, resulting from the hydrogen bonding between two adjacent carboxylate groups. In apparent complete dissociation, about 80, 60, and 40% of the itaconate residues bind to Li+, Na+, and K+ ions, respectively, when it is assumed that no (CH3)4N+ ions are bound to the carboxylate groups.

Journal

Citations (1)*help

See more

References(28)*help

See more

Details 詳細情報について

Report a problem

Back to top