Considering semi-crystallinity in molecular simulations of mechanical polymer properties – using nanoindentation of polyethylene as an example

Susanne Fritz1

1FILK Freiberg Institute gGmbH, Meißner Ring 1-5, 09599 Freiberg, Germany.

DOI:

https://doi.org/10.7494/cmms.2021.1.0747

Abstract:

Molecular dynamic (MD) simulations have been used to investigate the response of semi-crystalline polymers in nanoindentation tests, using polyethylene (PE) as an example. To that purpose, semi-crystalline simulation boxes of linear PE with various chain lengths up to C2000 were created by homogeneous nucleation during the non-isothermal cooling of melts. The final crystallinity depended on the chain length and the cooling rate used and could be estimated using various parameters like density, fraction of bonds in trans conformation, and energy terms. The simulation boxes were transferred into surface models and subjected to nanoindentation tests using non equilibrium MD. This allowed the deformation behaviour of the material to be analysed directly. Strong dependencies on the crystallinity of the PE were found, which underlines the importance of considering crystallinity when investigating the mechanical properties of semi-crystalline polymers by means of simulations.

Cite as:

Fritz, S. (2021). Considering semi-crystallinity in molecular simulations of mechanical polymer properties – using nanoindentation of polyethylene as an example. Computer Methods in Materials Science, 21(1), 35–50. https://doi.org/10.7494/cmms.2021.1.0747

Article (PDF):

Key words:

Molecular dynamic, Simulation, Polymer, Polyethylene, Semi-crystalline, Mechanical properties, Crystallization, Nanoindentation

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