(382i) Modeling of Excess Molar Volumes for Binary Liquid Mixtures Containing Water and Amines

In this study, data of excess molar volumes for binary mixtures of (water + propylamine, or + n-butylamine, or + s-butylamine, or + diethylamine, or + t-butylamine) have been used to test the applicability of the Prigogine-Flory-Patterson (PFP) Theory [1-4] and the Extended Real Associated Solution (ERAS) Model [5]. The excess molar volume predicted by the PFP-Theory is given by a sum of three contributions: (1) the interactional, which is proportional to Flory’s parameter (χ₁₂); (2) the free volume contribution, which depends on the difference in the expansion degree of components; (3) the P^* contribution, related to the differences in internal pressures and in reduced volumes of components. The ERAS-Model is a theoretical model based on a statistical mechanical derivation. It combines the Kretschmer-Wiebe Model of the linear successive association with Flory’s equation of state. In the light of the models, the results obtained by the adjustment of the model parameters reveal that the negative values experimentally observed of excess molar volumes for the systems studied can be explained by the assumption of hydrogen bonding between the unlike molecules.

References

[1] I. Prigogine. The molecular Theory of Solution, North-Holland Publishing Company, Amsterdam (1957).

[2] P.J. Flory, R.A. Orwoll, A. Vrij. J. Am. Chem. Soc., 86 (1964) 3507-3514.

[3] P.J. Flory, R.A. Orwoll, A. Vri. J. Am. Chem. Soc., 86 (1964) 3515-3520.

[4] D. Patterson, G. Delmas. Discuss. Faraday Soc., 49 (1970) 98-10.

[5] A. Heintz. Ber. Bunsenges. Phys. Chem., 89 (1985) 172-181.