Multiscale Modeling Scheme for Simulating Polymeric Melts: Application to Poly(Ethylene Oxide)

The poly(ethylene oxide) (PEO) is employed as one typical example to demonstrate a new multiscale modeling scheme for simulating high-molecular-weight polymeric melts. In this scheme, the structural distributions and the densities at five elevated temperatures at 1 atm, which are obtained from molecular dynamics (MD) simulations of all-atomistic oligomeric melt, are employed as the target functions to parameterize the coarse-grained (CG) potentials. The extensive CG MD simulations reproduce the densities at a wide temperature range, from which the glass transition temperatures (T-g) and the volumetric expansion coefficients can be determined for the PEO bulks. These results confirm that the so-developed CG potentials exhibit excellent chain-length and temperature transferability. Furthermore, some essential structural properties and dynamics speedup features are captured, and the latter qualitatively dictates the agreement in T-g. Such a scheme can play an important role in predicting thermomechanical properties of specific complex polymers.