Cohesive Origin of Cavitation in Polymer Networks

Cavitation in soft polymer networks is a critical yet poorly understood failure process that governs the performance of elastomers, gels, and adhesives. While well studied in fluids, cavitation in solids poses unique challenges due to the coupling between molecular cohesion, network architecture, and large non-affine deformation. Traditional continuum models describe cavity growth from bulk properties but cannot capture molecular-scale fluctuations that trigger cavitation. We address this through a multiscale framework combining a cohesive free-energy model inspired by van der Waals theory with discrete mesoscale network simulations that explicitly resolve crosslinks and many-body cohesive interactions. The simulations reproduce cavity nucleation, pressure drops, and volumetric instabilities consistent with theory, revealing how cohesion and strand extensibility control cavitation thresholds. This integrated framework links molecular cohesion to macroscopic failure, offering insights for designing tougher, cavitation-resistant materials.

This work is supported by 3M Company and the University of Colorado Boulder.