The pressure-volume-temperature (PVT) relationships of pure diisononyl phthalate (DINP) were measured at temperatures of 303.15–363.15 K and pressures up to 160 MPa by a variable-volume method. Using a synthetic method that involved observing the bubble point, the phase behavior of the CO₂/DINP binary system was also measured. The phase boundaries were determined at temperatures of 313.15–393.15 K and CO₂ molar fractions of 0.3–0.9. The characteristic parameters of DINP were obtained by correlating the measured PVT data using the Sanchez-Lacombe equation of state (SL EoS), and the bubble points of the system were correlated using the SL EoS with the determined characteristic parameters. The interaction parameter exhibited temperature dependence, and the introduction of the temperature dependence improved the correlation.

纯邻苯二甲酸二异壬酯 (DINP)的压力-体积-温度 ( PVT ) 关系是在 303.15–363.15 K 的温度和高达 160 MPa 的压力下通过可变体积方法测量的。使用涉及观察泡点的合成方法，还测量了 CO ₂ /DINP 二元体系的相行为。相边界是在 313.15-393.15 K 的温度和0.3-0.9 的CO ₂摩尔分数下确定的。DINP 的特征参数是通过关联测得的PVT得到的数据使用 Sanchez-Lacombe 状态方程 (SL EoS)，并且系统的泡点使用 SL EoS 与确定的特征参数相关联。相互作用参数表现出温度依赖性，温度依赖性的引入改善了相关性。