Force-Dependent Fracture of Dynamic Polymer Networks: Sacrificial Bond Rupture and Dispersion-Induced Physical Crosslinking
Year: 2026
Type: preprint
Abstract: We use coarse-grained molecular dynamics to investigate tensile fracture in dynamically crosslinked polymer networks, where both weak-linker and strong backbone bonds rupture according to Bell-model force-dependent probabilities. Competition between these pathways determines whether preferential weak-linker rupture relieves local stress, redistributes load, and protects the backbone. Lower linker activation energy or stretching stiffness promotes this sacrificial pathway, suppressing backbone rupture and delaying failure. Linker regeneration preserves connectivity but reloads the backbone, weakening sacrificial protection and reducing extensibility. Dispersion interactions between linker beads induce aggregation and physical crosslinking; moderate attraction reinforces the network, whereas stronger attraction suppresses weak-linker rupture, redirects load to the backbone, and causes embrittlement. Varying dynamic crosslinker content further tunes the balance between sacrificial weak-linker rupture and dispersion-induced reinforcement, with an intermediate content providing a favorable combination of stiffness, strength, and extensibility. These results identify force-dependent competition between weak and strong bonds as a unifying mechanism for polymer-network design.
Source: ChemRxiv
Authors: Wenjing Guo, Tao Zhang
Institution: Shanghai Jiao Tong University
Language: English
Subfield: Polymers and Plastics
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Awards: G5576671566, G5848258319
OpenAlex ID: W7207590149