Mesoscale modeling of mechanical responses in polymeric systems

For studying the mechanical responses of high molecular polymeric systems under uniaxial tension, we developed a mesoscale model to simulate and analyze the fracture behavior of bulk polymers and double layer cross-linked hydrogels generated by atom transfer radical polymerization (ATRP) in the framework of dissipative particle dynamics (DPD). We first validate the bond breaking model in the single-chain model and then apply the model to explore the mechanical behavior of the bulk polymers and two-layered hydrogels. With 50% of solvent, the bulk polymers are flexible as the polymer chains have freedom of movement. The bonds in the bulk system do not elongate much even the system is highly deformed. The two-layered hydrogels act tougher than the bulk polymers. In the two-layered hydrogel, the structure of polymer network determines the strength at small deformation when the chain movements are restricted and the bond properties determines the strength after the yield happens.