writer：Chaofu Wu
keywords：coarse-graining; molecular dynamics; multiscale simulations; phase morphologies; polymer blends
source：期刊
specific source：Macromolecular Theory and Simulations 2016; 25(4): 336-347
Issue time：2016年

In this work, the combined iterative Boltzmann inversion/conditional reversible work scheme is extended with a little modifications to derive the systematically coarse-grained (CG) potentials for simulating two typical atactic polymer blends composed of poly(methyl methacrylate) (PMMA) and poly(vinyl chloride) (PVC) or polystyrene (PS). Molecular dynamics simulations are extensively performed on the two blends with a wide formulation range. It is revealed by these simulations that, throughout the entire composition range, the PMMA/PVC blend is homogeneous whereas the PMMA/PS blend undergoes phase separation, which agrees well with the experimental observation that the former exhibits strong interactions that are absent in the latter. Depending upon the formulation, the immiscible PMMA/PS blend presents one single- or double-continuous phase. It is further confirmed that intermolecular interactions play the key roles in forming the phase morphologies, which in turn can be inferred from only the three nonbonded CG potentials of one unlike pair and two like pairs.

https://onlinelibrary.wiley.com/doi/abs/10.1002/mats.201500087