Abstract The (p, ρ, T) behavior of propylene glycol was investigated in the homogeneous liquid phase over the temperature range from (272.7 to 393.0) K at pressures from (5.0 to 91.4) MPa. A commercially-available high-pressure vibrating-tube densimeter was utilized to perform the measurements. The measuring system was calibrated by using water and helium as reference fluids, and the calibrated system was validated by measurements of argon and propane. Prior to the measurements, the propylene glycol sample with a purity of 98.8 mol-% was degassed by several freeze-pump-thaw cycles. Considering the measurement uncertainties in temperature, pressure and oscillation period, and uncertainties resulting from instrument calibration and sample impurities, the combined expanded uncertainty (k = 2) in density was estimated to be 1.78 kg·m−3. Using the new experimental data, a correlation equation for the (p, ρ, T) behavior of propylene glycol was established; in the investigated (p, T) range, the combined expanded uncertainty (k = 2) is also 1.78 kg·m−3. The agreement of the carefully selected experimental data from literature and the correlation equation is within the uncertainty of the equation.

中文翻译：

---

在 (283.3 到 393.1) K 的温度和高达 100.1 MPa 的压力下液体乙二醇的 (p, ρ, T) 行为的测量和相关性

摘要 在 (272.7 到 393.0) K 的温度范围内，在 (5.0 到 91.4) MPa 的压力下，研究了丙二醇在均相液相中的 (p, ρ, T) 行为。使用市售的高压振动管密度计进行测量。使用水和氦气作为参考流体校准测量系统，并通过测量氩气和丙烷来验证校准系统。在测量之前，纯度为 98.8 mol-% 的丙二醇样品通过几次冻-泵-解冻循环脱气。考虑到温度、压力和振荡周期的测量不确定度，以及仪器校准和样品杂质导致的不确定度，密度的综合扩展不确定度 (k = 2) 估计为 1.78 kg·m-3。利用新的实验数据，建立了丙二醇(p, ρ, T)行为的相关方程；在研究的 (p, T) 范围内，组合扩展不确定度 (k = 2) 也是 1.78 kg·m−3。从文献中精心挑选的实验数据与相关方程的一致性在方程的不确定性范围内。