Transferable coarse-grained models for poly(ethylene oxide)/poly(methyl methacrylate) blends

The recently developed multiscale scheme has been extended to parameterize the coarse-grained (CG) potentials for simulating the two binary blends comprised of poly(ethylene oxide) (PEO) and isotactic or syndiotactic poly (methyl methacrylate) (iPMMA, sPMMA). The specific volumes and the non-bonded interaction energies reveal a single glass transition temperature (Tg), and the dynamical Tg and chain dimension exhibit a strong composition-dependence, and the scale-dependent miscibility is confirmed. As inferred from the intermolecular radial distribution function (RDF), sPMMA is more miscible with PEO than is iPMMA. For any of these systems, the heats and free energies of mixing are most negative at the middle composition. More negative free energy of mixing at lower temperature predicts a lower critical solution temperature. All these simulated results are in good agreements with the experimental observations, validating the multiscale scheme with the ability to derive the transferable CG potentials.