For separation of the azeotrope isopropyl alcohol and diisopropyl ether by extractive distillation, 2-ethoxyethanol and butyl acetate were adopted as extractive solvents, and the vapour-liquid equilibrium data for the binary systems of isopropyl alcohol + 2-ethoxyethanol, isopropyl alcohol + butyl acetate, diisopropyl ether + 2-ethoxyethanol and diisopropyl ether + butyl acetate were measured at 101.3 kPa by a modified Rose type recirculating still. The Herington and van Ness consistency method were used to check the thermodynamic consistency of the VLE data. Meanwhile, the VLE data were correlated using the NRTL, UNIQUAC and Wilson models, and the binary interaction parameters of the three models were regressed. The correlation results indicate that the three models can correlate the experimental data with the root-mean-square deviation value of vapour phase mole faction less than 0.0062. Finally, an extractive distillation process for separating the azeotrope of isopropyl alcohol and diisopropyl ether is explored in this work. (C) 2018 Elsevier Ltd.