PVT properties for binary ionic liquids of 1-methyl-1-propylpiperidinium bis(trifluoromethylsulfonyl)imide with anisole or acetophenone at pressures up to 50 MPa

Densities of pure 1-methyl-1-propylpiperidinium bis(trifluoromethylsulfonyl)imide, [C3mpip][NTf2], and its mixtures with anisole or acetophenone were measured with a high-pressure densimeter at temperatures from 298.15 K to 348.15 K and pressures up to 50 MPa. The Tait equation was employed to represent pressure effect on the isothermal densities. The experimental results reveal that the excess volumes of (anisole + [C3mpip][NTf2]) and (acetophenone + [C3mpip][NTf2]) are all negative over the entire experimental conditions. In addition to an empirical generalized equation, the density data were also correlated quantitatively with the Flory–Orwoll–Vrij (FOV) and the Schotte equations of state.

► The densities were measured with a high-pressure densimeter. ► The systems are ionic liquid [C3mpip][NTf2] with anisole or acetophenone. ► The densities data fitted accurately to the Tait equation. ► The excess volumes are all negative over the entire experimental conditions. ► The FOV and Schotte equations of state are correlated well the density data.