Coarse-Grained Molecular Dynamics Simulations of Dynamic Bond Elastomers Using Interbead Potentials for Entropy- and Enthalpy-Driven Mechanisms in Their Dynamics and Mechanical Properties

Dynamic bond elastomers are currently attracting considerable attention owing to their unique mechanical properties. The toughness and self-healing properties of these materials are controlled by the association-dissociation dynamics of the cross-links. In this study, we observed and analyzed these dynamics by creating models of dynamic bond elastomers based on coarse-graining techniques and by performing equilibrium and uniaxial elongation simulations. In the equilibrium simulations, the association-dissociation dynamics of our model were inferred from estimated association constants, which are controlled by the bond dissociation energy. In the elongation simulations, we obtained the properties of cyclic deformation and self-healing, which are features of dynamic bond elastomers in real synthetic materials. These properties can be tuned by altering the balance between the entropy and enthalpy changes through association and dissociation.