An Efficient Method to Generate Dense Amorphous Structures for Molecular Simulation of Vinyl Polymers

Abstract

An efficient technique to construct dense amorphous polymers at the bulk density is illustrated for two vinyl polymers, i.e., PVX, –[CH2–CH(X)]–. Bulk amorphous polypropylene (PP) and polystyrene (PS) structures are generated starting from coarse‐graining polymer chains and are mapped onto the second nearest neighbor diamond (2nnd) lattice. PVX are represented by the rotational isomeric state (RIS) model and non‐bonded interactions are treated by the Lennard–Jones (LJ) potential function. Lattice Monte Carlo (MC) simulation is utilized to equilibrate coarse‐grained (C) PVX and the fully atomistic models can be recovered by the reverse‐mapping procedure to restore the missing atoms. After geometry optimization, chain and material properties of bulk PVX structure are computed to validate the atomistic models including conformational characteristics, Hildebrand solubility parameter, pair correlation function, and scattering structure factor.