乙酸乙酯-1,2-丙二醇二元系的密度、折射率和黏度

Density,refractive index and viscosity of binary mixture of ethyl acetate and 1,2-propanediol

常压下测定了乙酸乙酯和1,2-丙二醇二元系在298.15~323.15 K下的密度、折射率和黏度,建立了混合液密度、黏度随组成和温度变化关系的方程。计算了过量摩尔体积VE,折射率偏差ΔnD,黏度偏差Δη和过量流动活化自由能ΔG＊E。结果表明,过量摩尔体积低温时在全浓度范围内为负值,但随温度升高,在富酯区变为正值;而折射率偏差高温时在富醇区为微小正值,其他情况都是负值;黏度偏差和过量流动活化自由能显示了相同的变化关系,均为负值,且都随温度降低而偏差增大。

The densities,refractive indices,and viscosities of ethyl acetate ＋ 1,2-propanediol binary mixture were measured at temperatures in the range of 298.15—323.15 K and atmospheric pressure using pycnometer,ABBE refractometer and Ubbelohde viscometer respectively.The density and viscosity data are fitted as a function of composition and temperature.Excess molar volumes（VE）,refractive index deviations（ΔnD）,viscosity deviations（Δη）and excess Gibbs energy of activation of viscous flow（ΔG＊E）are calculated from the experimental data.The results show that the excess molar volumes are negative at 298.15 K and 303.15 K,but they turn to be positive in the rich ester region with rising of temperature.The refractive index deviations are negative except in the rich alcohol region.Both Δη and ΔG＊E are negative over the whole mole fraction range in the temperature range studied,and the deviations is greater as temperature decreases.