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BIBTEX RIS

Contributions to the thermodynamics of polymer hydrogel systems

2003; Elsevier BV; Volume: 45; Issue: 4 Linguagem: Inglês

10.1016/j.polymer.2003.11.048

1873-2291

Éder Domingos de Oliveira, Antônio F.S. Silva, Roberto F. S. Freitas,

Advanced Sensor and Energy Harvesting Materials

In this work, an extended version of a quasichemical thermodynamic model is presented. The swelling behavior of crosslinked acrylamide polymer gels and N-substituted derivatives, such as N-isopropylacrylamide and N-tert-butylacrylamide has been compared to predictions from such model which takes into account the specific hydrogen bonding interactions encountered in these systems. The calculated volume transition temperature of the poly(N-isopropylacrylamide) gel is 0.8 °C lower than the experimental value and the predicted solvent volume fraction in the collapsed and swollen gel states are about 2% larger than the corresponding experimental data measured at the transition point. Applying the same energy parameters obtained from regressing poly(N-isopropylacrylamide) gel swelling pressure data, the model has also been capable to correctly represent the major features found in the swelling behavior of linear poly(N-tert-butylacrylamide) and poly(N-tert-butylacrylamide) gels, after the model parameters that characterize the molecular structure were changed in accord to each polymer repetitive unit.