A molecular dynamics study of the effect of pre-deformation on compression of glassy polymers*

Previous and ongoing experimental studies have revealed intriguing effects of melt stretching on uniaxial extension and compression. For example, brittle PS turns ductile during extension after melt stretching.¹ The effect is different for the same melt-stretched PS and PMMA on compression.² We carry out molecular dynamic (MD) simulation using coarse-grained models for PS and PMMA to explore the molecular mechanism leading to activation of the glassy state during either extension or compression. In addition, the MD simulation allows us to reveal that the origin of stress in response to extension is different from that in compression.

1. Zartman, G. D.; Cheng, S.; Li, X.; Lin, F.; Becker, M. L.; Wang, S.-Q. Macromolecules 2012, 45, (16), 6719-6732.
2. Jianning Liu and S. Q. Wang, unpublished.