Void nucleation and disentanglement in glassy amorphous polymers.

Area of Science:

• Polymer Science
• Materials Science
• Computational Materials Science

Background:

• Cavitation in glassy polymers is linked to high triaxial stress and impurities.
• Understanding void nucleation is vital as cavities precede crazes and fracture.

Purpose of the Study:

• To investigate the early stages of void nucleation in glassy amorphous polymers.
• To analyze the role of the entanglement network during cavitation.

Main Methods:

• Utilized molecular dynamics simulations.
• Imposed highly triaxial stress states on entangled linear macromolecular chains.
• Monitored the evolution of the polymer entanglement network.

Main Results:

• Deformation-induced disentanglement significantly impacts early void nucleation.
• Rearrangement of topological constraints along polymer chains is important.
• Significant changes in rheological constraints occur even in the glassy state.

Conclusions:

• Chain disentanglement and topological rearrangements are key mechanisms in polymer cavitation.
• The study highlights the importance of molecular-level dynamics in macroscopic material failure.