Coarse-grained modeling and multi-properties simulation of amorphous polyethylene

In this paper, a coarse-grained (CG) model of amorphous polyethylene (PE) has been developed, and the potential parameters of CG have also been derived. Accordingly, the multi-properties of amorphous PE such as its density, glass transition temperature (T_g), mechanical and thermal properties are studied by using Coarse-Grained Molecular Dynamics (CGMD) simulations. The potential parameters of CG model have been derived via an iterative Boltzmann inversion (IBI) method, and the bond lengths, bond angles and pair distributions obtained in CGMD simulations match well with those obtained in all-atom molecular dynamics (AAMD) simulations. The obtained potential parameters can be utilized to accurately reproduce the density, T_g and mechanical properties of amorphous PE, but the thermal conductivity returned by the CG model is only 1/2 of the actual value. Furthermore, the reasons for the lower thermal conductivity are discussed.