Excess molar enthalpies of R-fenchone + butan-1-ol or + pentan-1-ol. Modeling with COSMO-RS and UNIFAC

Highlights: • $H_{\text{m}}^{\text{E}}$, of the binary liquid mixtures R-fenchone + butan-1-ol or pentan-1-ol, were measured. • $H_{\text{m}}^{\text{E}}$ maxima range from 1119 (283.15 K) to 1457 J·mol⁻¹(328.15 K) for (R-fenchone + butan-1-ol). • $H_{\text{m}}^{\text{E}}$ maxima range from 1154 (283.15 K) to 1459 J·mol⁻¹(328.15 K) for (R-fenchone + pentan-1-ol). • UNIFAC provides better predictions for $H_{\text{m}}^{\text{E}}$ than COSMO-RS for both mixtures. • UNIFAC provides fair predictions of $H_{\text{m}}^{\text{E}}$ for both mixtures (maximum Δ_AAD of 10.4). In this paper, experimental isobaric excess molar enthalpies for the binary mixtures of R-fenchone with butan-1-ol or pentan-1-ol at four temperatures (283.15, 298.15, 313.15 and 328.15) K and atmospheric pressure are reported over the entire composition range. They have been fitted to the Redlich–Kister equation at each temperature. Excess molar enthalpies are positive in all cases, being slightly greater for the mixture with pentan-1-ol than for the mixture with butan-1-ol. These positive values of the excess molar enthalpy suggest the predominance of both the effect due to hydrogen bond breaking and physical interactions over the interaction between dissimilar molecules in the mixture. Finally UNIFAC (Dortmund) method and the Quantum Continuum Method COSMO-RS have been used to predict the excess molar enthalpies. Better predictions are obtained in the case of the UNIFAC model. These experimental and modeling results obtained for excess molar enthalpies together with our previously reported ones are jointly discussed to cover binary mixtures containing R-fenchone with short chain alkan-1-ols (C₂–C₅).