Atomic Scale Deformation Mechanisms of Amorphous Polyethylene under Tensile Loading

MA Tschopp and JL Bouvard and DK Ward and MF Horstemeyer, TMS2011 SUPPLEMENTAL PROCEEDINGS, VOL 2: MATERIALS FABRICATION, PROPERTIES, CHARACTERIZATION, AND MODELING, 789-794 (2011).

The molecular origin of plastic deformation within amorphous polymers is an important issue that is still not well understood. Here, we investigate the deformation mechanisms of amorphous polyethylene. Molecular dynamics simulations were used to apply a tensile load to amorphous polyethylene using a united atom model. A range of strain rates, chain lengths and chain numbers were sampled to investigate the stress-strain behavior and associated deformation mechanisms. The large range in these conditions (e. g., 100 times difference in strain rate) provided the contrast in response necessary to elucidate the relationship between intrachain (Van der Waal's interactions) and interchain (dihedral rotations) deformation mechanisms in amorphous polyethylene. Simulation results show how internal mechanisms associated with chain rotation and entanglement evolve with increasing deformation. These results provide insight into the evolution of internal state variables for multiscale models of thermoplastic polymers.

Return to Publications page