Static Relative Permittivities of Water + 1-Methyl-2-pyrrolidinone and Water + 1,3-Dimethyl-2-imidazolidinone Mixtures under Pressures up to 300 MPa at 298.15 K

Static relative permittivities ε r of water + 1-methyl-2-pyrrolidinone and water + 1,3-dimethyl-2-imidazolidinone mixtures have been measured over the whole mole-fraction range under pressures up to 300 MPa at 298.15 K. The experimental results as a function of pressure P for each mixture were fitted to the Tait-type equation, and the Tait-type parameters, A and B, were determined. Values of (∂ ln ε r /∂ P ) T and ε r - 2 (∂ε r /∂ P ) T at 0.1 MPa for both binary aqueous mixtures were evaluated from the static relative permittivity at 0.1 MPa, ε r (0.1), and the Tait-type parameters and compared with each other. For the water + 1-methyl-2-pyrrolidinone mixture, values of (∂ ln ε r /∂ P ) T and the isothermal compressibility κ T at 0.1 MPa as a function of composition were also compared.