聚苯乙烯与溶剂体系相容性的计算机模拟

使用推广的 Flory-Huggins理论结合 Monte Carlo法模拟聚苯乙烯与几种不同溶剂的相容性。用 Monte Carlo法从大量分子对中取样 ,计算配位数和相互作用能 ,将数据输入 Flory-Huggins格子模型中 ,估算出体系的混合自由能和相图 ,研究聚合度对聚苯乙烯与溶剂体系相容性的影响。模拟结果表明聚苯乙烯与甲苯等溶剂的相容性较好 ,与水等溶剂的相容性较差 ;随着聚苯乙烯聚合度增大 ,体系相容性变差 ;而且在聚合度较低时 ,相容性变差的程度更显著 ;以上结果与实际情况相符。

Computer Simulation of Miscibility of Polystyrene and Solvents System

The miscibility behavior of polystyrene and several different solvents was studied by using a combination of a generalized Flory-Huggins theory and Monte Carlo simulation method. The Monte Carlo method has been used to sample from thousands of molecular pairs, then coordination numbers and interaction energies can be computed. These data can be put into the generalized Floly-Huggins lattice model in order to produce an estimated free energy of mixing and phase diagram, the influence of polymerization degree on miscibility behavior of polystyrene and solvent can be studied. From the simulation results, it can be found that the miscibility of polystyrene and several solvents (e.g. methylbenzene) is better, however, the miscibility of polystyrene and other solvents(e.g. water) is worse. The miscibility of the system become worse when the polymerization degree of polystyrene has been increased. These changes are remarkable in lower polymerization degree. All the results coincide with the facts.