# Modeling elastic properties of polystyrene through coarse-grained molecular dynamics simulations

## TL;DR

This study uses extended coarse-grained molecular dynamics simulations with the MARTINI force field to analyze and tune the elastic properties of polystyrene, aligning simulation results with experimental data.

## Contribution

It introduces modifications to the MARTINI force field to better replicate the elastic properties of polystyrene in molecular dynamics simulations.

## Key findings

- Simulations successfully reproduce experimental elastic moduli of polystyrene.
- Iterative force field modifications improve shear and bulk modulus accuracy.
- Extended $s$-scale simulations capture slow relaxation processes.

## Abstract

This paper presents an extended coarse-grained investigation of the elastic properties of polystyrene. In particular, we employ the well-known MARTINI force field and its modifications to perform extended molecular dynamics simulations at the $\mu$s timescale, which take slow relaxation processes of polystyrene into account, such that the simulations permit analyzing the bulk modulus, the shear modulus, and the Poisson ratio. We show that through the iterative modification of MARTINI force field parameters it turns out to be possible to affect the shear modulus and the bulk modulus of the system, making them closer to those values reported in the experiment.