The authors have measured the vapour pressure of the binary four systems, piperidin +1,4-dioxan, piperidin+tetrahydropyran,
piperidin+tert-butyl methyl ether and N-methyl piperidin+tert-butyl methyl ether. The measurements were carried out using an isoteniscope built by J. Jose . The vapour pressure, excess
Gibbs free energies at 298.15 K, 303.15 K, 313.15 K, 323.15 K, 333.15 K and 343.15 K, are reported for these mixtures. The
excess Gibbs free energies have been fitted to the Redlich-Kister equation.