(352aa) Volumetric Properties of Binary Mixtures of N-butylammonium Lactate Ionic Liquid with Ethanol

Ionic liquids (ILs) are defined as salts, which have melting point below 100°C whereas room temperature ionic liquids (RTIL) are liquids. Recent years, ILs attracted a large attention from the scientific and industrial community, because many of these compounds have good solubility in organic and inorganic solvents, low volatility, good chemical and thermal stability and are normally a green solvent. These special properties and diversities of ILs is growing in many applications of chemical industries.

Our previous studies have focused on the binary liquid mixtures containing varied protic ionic liquids with alcohols [1; 2; 3]. This work is a continuation of volumetric and spectroscopic studies of the mixtures of ionic liquid {n-butylammonium lactate + ethanol} in the whole concentration range at different temperatures T = (293.15 – 308.15) K under atmospheric pressure. The experimental data of density was used to calculate some volumetric properties (excess molar volume, partial molar volume, apparent molar volume, partial molar excess volumes and their infinite dilution). In addition, the Redlich-Kister equation was used to correlate the excess molar volume and it was in good agreement with the experimental values.

N-butylammonium lactate was synthesized in our laboratory by neutralization, using n-butylamine and lactic acid, and was characterized by using ¹H-NMR, ¹³C-NMR and FTIR spectroscopy techniques and presented a purity more than 96 %. The densities of pure components and their solutions were measured using a oscillating U-tube density meter from Anton Paar (model DMA 4500). The analysis of ¹H-NMR and ¹³C-NMR were obtained in an Avance III 600 HD Bruker spectrometer operating at 600 MHz for protons and 150 MHz for carbon. The IR spectra were obtained in Fourier transform infrared spectroscopy Nicolet with attenuated total reflectance (FTIR-ATR) (model 6700).

For all systems studied, the values of excess molar volumes were negative over the entire composition range. The results obtained were discussed in terms of intermolecular interactions, particularly hydrogen-bonding interactions between like and unlike molecules.

References

[1] S.S. Bittencourt, H.E. Hoga, R.B. Torres, J.V.H. D’Angelo, J. Chem. Thermodyn. 105 (2017) 238-252.

[2] S.S. Bittencourt, H.E. Hoga, R.B. Torres, J.V.H. D’Angelo, J. Therm. Anal. Calorim. (2018).

[3] G.V. Olivieri, C.S. da Cunha, L.D. Martins, P.A.M. Paegle, S.D. Nuncio, A.D. Morandim-Giannetti, R.B. Torres, J. Therm. Anal. Calorim. 131 (2018) 2925-2942.