Thermodynamics of mixtures with strongly negative deviations from Raoult's law. XI. Densities, viscosities and refractives indices at (293.15-303.15) K for cyclohexylamine + 1-propanol, or +1-butanol systems

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• 作者：Luis F. Sanz ; Juan A. Gonz¨¢lez ; Isas¨ªas Garc¨ªa De La Fuente ; Jos¨¦ C. Cobos
• 关键词：Cyclohexylamine ; 1-alkanols ; Excess molar volumes ; Viscosities ; Refractive indices ; Interactions
• 刊名：Journal of Molecular Liquids
• 出版年：2012
• 出版时间：August, 2012
• 年：2012
• 卷：172
• 期：Complete
• 页码：26-33
• 全文大小：408 K

文摘

The thermophysical properties densities, ¦Ñ, kinetic viscosities, ¦Í, and refractive indices, n_D, have been measured at atmospheric pressure and at (293.15-303.15) K for the mixtures cyclohexylamine + 1-propanol, or +1-butanol. The experimental ¦Ñ, ¦Í, n_D values were obtained using an Anton Paar DMA 602 vibrating-tube densimeter, an Ubbelohde viscosimeter and a refractometer model RMF970, respectively. Densities values are used to determine the molar excess volumes, V_m^E, and, together with ¦Í values, the dynamic viscosities (¦Ç). Deviations from the ideal state,¦¤n_D, and deviation from linear dependence on mole fraction for viscosity, ¦¤¦Ç, are also reported. The large negative V_m^E values obtained reveal the existence of strong interactions between unlike molecules. This is supported by the positive values of ¦¤¦Ç and by the quadratic dependence of n_Dwith mole fraction. The temperature dependences of ¦Ç and of the molar volume have been used to evaluate the enthalpy and entropy of viscous flow. It is shown that Gibbs energy of viscous flow,¦¤G*, is essentially determined by enthalpic effects. Viscosity data have been correlated by the semi-empirical equations: Grunberg-Nissan, Hind, Frenkel, Katti-Chaudhri, Teja-Rice, McAllister and Heric. The deviations obtained are between 1 % and 2