Measurement and correlation of vapor–liquid equilibra for cyclohexane + ethylene glycol monoisopropyl ether and cyclohexane + ethylene glycol monoisobutyl ether systems

Ethylene glycol monoisopropyl ether (iC3E1) and ethylene glycol monoisobutyl ether (iC4E1) are nonionic surfactants which have been attracting considerable attention due to inter and intra-molecular association, related to the presence of O and OH in the same molecule. Binary isothermal vapor + liquid equilibrium data were measured for cyclohexane + ethylene glycol monoisopropyl ether and cyclohexane + ethylene glycol monoisobutyl ether systems at four different temperatures ranging from 303.15 K to 333.15 K at 10 K intervals. A static apparatus was used in this study. Two systems show positive deviation from Raoult's law and no azeotrope. The experimental data were correlated well with Peng–Robinson–Stryjek–Vera equation of state using Wong–Sandler mixing rule.