Density, speed of sound, and refractive index measurements were conducted for butan-1-ol + butane-1,4-diol/butane-2,3-diol mixtures in the temperature range of (298.15–338.15) K and at atmospheric pressure (0.101 MPa). These properties were found to exhibit nonlinear trends with composition, indicating that the mixtures behave nonideally. To quantify these nonidealities, the data were used to calculate various thermodynamic properties including the excess molar volume, deviation in speed of sound, excess isentropic compressibility, deviation in thermal expansivity, and deviation in refractive index. A comparison of excess/deviation property behaviors of the two butanediol isomers in butan-1-ol revealed dissimilar results, with the excess molar volume for the butan-1-ol + butane-1,4-diol system exhibiting a negative excess molar volume of 1 order of magnitude larger than the butan-1-ol + butane-2,3-diol system, which decreased with temperature, with minima at approximately x₁ = 0.5. The excess molar volumes in the butan-1-ol + butane-2,3-diol systems were approaching zero and transitioning to positive values with the decrease in temperature and with minima at approximately x₁ = 0.6. Similar behaviors between the two systems were observed for the deviation in speed of sound, exhibiting maxima between x₁ = 0.35 and 0.45. The deviation in refractive index behaviors was similar in shape for both systems (positive deviation); however, the magnitudes of the deviation were approximately twice as large in the butan-1-ol + butane-2,3-diol systems. The calculated excess/deviation properties were fitted to Redlich–Kister polynomials mostly within experimental uncertainty.

中文翻译：

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丁烷-1-醇 (1) + 丁烷-1,4-二醇 (2)/丁烷-2,3-二醇 (2) 混合物的密度、声速和折射率数据在 T = (298.15–338.15) K 和 0.101 兆帕

在 (298.15–338.15) K 的温度范围内和大气压下对丁烷-1-醇 + 丁烷-1,4-二醇/丁烷-2,3-二醇混合物进行密度、声速和折射率测量(0.101 兆帕)。发现这些特性表现出随组成的非线性趋势，表明混合物表现非理想。为了量化这些非理想性，数据用于计算各种热力学特性，包括过量摩尔体积、声速偏差、过量等熵压缩率、热膨胀率偏差和折射率偏差。对 butan-1-ol 中两种丁二醇异构体的过量/偏差特性行为的比较揭示了不同的结果，butan-1-ol + butane-1 的摩尔体积过量，x ₁ = 0.5。丁烷-1-醇 + 丁烷-2,3-二醇系统中的过量摩尔体积接近于零，并随着温度的降低而转变为正值，最小值约为x ₁ = 0.6。对于声速偏差，观察到两个系统之间的类似行为，在x ₁ = 0.35 和 0.45之间表现出最大值。两种系统的折射率行为偏差在形状上相似（正偏差）；然而，在丁烷-1-醇 + 丁烷-2,3-二醇系统中，偏差的幅度大约是原来的两倍。计算出的过量/偏差特性主要在实验不确定性内拟合到 Redlich-Kister 多项式。