Valencia, JoaquínBaselga Llidó, JuanEsteban Pacios, María IsabelFernández de Piérola, Inés2017-11-162017-11-162003-10Valencia, J., Baselga, J., E. Pacios, I. & F. Piérola, I. (2003). Compression elastic modulus of neutral and protonated poly(N-vinylimidazole) hydrogels. Macromolecular Symposia. Functional Networks and Gels, 200 (1), pp. 235-242.1521-3900https://hdl.handle.net/10016/25859The compression modulus of poly(N-vinylimidazole) (PVI) hydrogels synthesized by cross-linking polymerization in aqueous solution, was measured at room temperature in several related systems: i) just after polymerization, ii) swollen at equilibrium in deionized water, iii) swollen in HCl (aq) (pH=2.5), iv) swollen in HCl (pH=2.5) and 1 M NaCl (aq) solution and v) swollen in H2SO4 (pH=2.5) (aq) solution. Samples of the first and second groups are neutral whereas hydrogels of the other three groups are ionic because of protonation of basic imidazole groups. The experimental results were fitted with the Erman-Monnerie theory, applied to compression measurements for the first time, to determine the phantom modulus, [fₚₕ*], and the parameter κG which measures the constraining role of entanglements on the fluctuations of chains between knots.8application/pdfeng© Wiley, 2003CompressionElastic modulusHydrogelsIonic gelsSwellingresearch articleMaterialesQuímicahttps://doi.org/10.1002/masy.200351024open access2351242Macromolecular Symposia. Special Issue: Functional Networks and Gels200AR/0000010948