Molecular Simulations of Vapor–Liquid Equilibrium of Isocyanates
Molecular Simulations of Vapor–Liquid Equilibrium of Isocyanates
复制标题
异氰酸酯汽液平衡的分子模拟
DOI：
10.1021/acs.jpcb.1c07132
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Gor, Gennady Y.
中科院分区：
文献类型：
--
作者：
Emelianova, Alina;Gor, Gennady Y.
异氰酸酯在多个行业中的广泛应用引发了对其相行为研究的兴趣。分子模拟是一种强大的工具，可以超越依赖于化学品分子结构的实验研究。分子模拟的成功依赖于对系统的描述，即力场，及其对感兴趣的再现性质的参数化。在这项工作中，我们提出了一个基于相平衡可转移势（TraPPE）的联合原子力场来模拟异氰酸酯的汽液相行为。采用Monte Carlo和分子动力学模拟方法，在力场作用下，模拟了一类线性单异氰酸酯（从异氰酸甲酯到异氰酸己酯，再到二异氰酸酯）的汽液平衡。此外，我们进行了类似的计算甲基，乙基和丁基异氰酸酯的基础上，在文献中的所有原子GAFF-IC力场建模异氰酸酯粘度。我们表明，开发的基于TrapPE的力场通常优于GAFF-IC力场，并且总体上在异氰酸酯的相行为建模中表现出优异的性能。基于所考虑的化合物的模拟蒸气压，我们估计了安托万方程参数，以计算在一定温度范围内的蒸气压。预测是特别有用的那些异氰酸酯缺乏实验蒸汽压数据的热力学性质的调查。结果也可以用于模拟异氰酸酯混合物的相行为，以研究其传感和捕获。此外，从汽液平衡的双节点，我们预测的临界性质，可用于基于状态方程的热力学模型的异氰酸酯。
The wide range of applications of the isocyanates across multiple industries sparks the interest in the study of their phase behavior. A molecular simulation is a powerful tool that can go beyond experimental investigations relying on a molecular structure of a chemical. The success of a molecular simulation relies on a description of the system, namely, force field, and its parameterization on reproducing properties of interest. In this work, we propose a united-atom force field based on the transferable potentials for phase equilibria (TraPPE) to model the vapor–liquid phase behavior of isocyanates. With Monte Carlo and molecular dynamics simulation methods and the introduced force field, we modeled vapor–liquid equilibrium for a family of linear mono-isocyanates, from methyl isocyanate to hexyl isocyanate, and hexamethylene diisocyanate. Additionally, we performed similar calculations for methyl, ethyl, and butyl isocyanates based on the all-atom GAFF-IC force field available in the literature for modeling isocyanate viscosities. We showed that the developed TraPPE-based force field generally overperformed the GAFF-IC force field and overall showed excellent performance in modeling phase behavior of isocyanates. Based on the simulated vapor pressures for the considered compounds, we estimated the Antoine equation parameters to calculate the vapor pressure in a range of temperatures. The predictions are of particular use in the investigation of thermodynamic properties for those isocyanates lacking experimental vapor pressure data. Results can also be employed in modeling the phase behavior of isocyanate mixtures to investigate their sensing and capturing. Furthermore, from the vapor–liquid equilibrium binodals, we predicted the critical properties of isocyanates which can be used in thermodynamic models based on an equation of state.