Bond dissociation in polymers under shock loading

Polymers are subjected to numerous shock loading situations. Even though there have been numerous works on polymers, the behavior of polymer under shock loading is yet to be fundamentally understood. Lack of consolidated fundamental understanding is primarily due to complexity associated with the molecular structure of polymers. Based on molecular structure, polymers can be grouped into two main classes: thermoset and thermoplastics. The behavior of these two classes of polymers are also significantly different with thermoplastics having linear entangled chain like structure whereas thermosets having a 3d network structure developed upon cross-linking. Shock simulations on a thermoplastic and a thermoset polymer has been demonstrated in this DFT/MD based numerical study. The bond dissociation energies required for thermoset polymers are observed to be significantly larger primarily because of strong intermolecular bonds. Bond dissociation mechanism at different shock strengths for these two classes of polymers have been elaborated upon in this study.