Abstract
Thermodynamic parameters for acid dissociation of the conjugate acids of poly(N-vinylimidazole) and polyallylamine have been determined in the presence of sodium chloride and sodium nitrate. Even though the plots of ΔG 0 against the degree of dissociation, α, are highly dependent on the added salt concentration levels, the concentration effect has never been observed for the corresponding ΔH 0 versus α plots. The effect on the ΔG 0 versus α plots has been attributed to the entropy change of the counterions between a polyelectrolyte phase and a bulk solution phase. The α dependency of ΔH 0 is affected remarkably by the kinds of cationic polymers and counter-anions. Each ΔH 0 value at completely neutralized conditions is quite close to the corresponding ΔH 0 value of the monomer analog. The difference in the ΔH 0 values at fully charged conditions has been explained by the heats due to
The ion-pair formation of chloride anion to the conjugate acids of poly(N-vinylimidazole) and polyallylamine has been supported by 35Cl NMR measurement. It has also been suggested that chloride anions bind the basic polymer molecules even at fully neutralized conditions.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 2 June 1999/Accepted in revised form: 19 July 1999
Rights and permissions
About this article
Cite this article
Kodama, H., Miyajima, T., Tabuchi, H. et al. A calorimetric study of the acid dissociation of the conjugate acids of poly(N-vinylimidazole) and polyallylamine. Colloid Polym Sci 278, 1–7 (2000). https://doi.org/10.1007/s003960050001
Issue Date:
DOI: https://doi.org/10.1007/s003960050001