Transferability of a coarse-grained atactic polystyrene model: Thermodynamics and structure

Abstract

In this paper, we construct a one-bead per monomer coarse grained (CG) model for atactic polystyrene (PS) via a combined structure-based and thermodynamic quantity-based CG method at 1 atm and 463 K by using the hard LJ 12–6 potential as the non-bonded interaction potential and applying iterative Boltzmann inversion method to derive the bonded potentials. Although the CG force field is built at one single thermodynamic state point without any temperature correction or pressure optimization terms, the CG model possesses a rather favorable transferability in a wide temperature of 100–600 K. More importantly, the CG model gives the glass transition temperature of 382 K, which is very close to the atomistic result of 360 K and the experimental value of 363 K. Additionally, the unique double-peak feature and the unusual temperature dependence of the polymerization peak in the experimental scattering spectrum of atactic PS are well captured by the systematic CG model.