Exploring the Effects of Nanoparticle Loading, Dispersion and Structure on the Stress Response of Elastomeric Nanocomposites*

For over a century, nanoparticles have been utilized to mechanically reinforce elastomers. Evidence spanning several decades suggests that yielding of the percolating filler network, occurring at strains on the order of 10%, leads to softening, a phenomenon known as the Payne effect. However, the microscopic origins of the dissipative nature and mechanical reinforcement of the elastomer beyond this point in the nonlinear deformation regime remain the subject of debate. Understanding these underlying mechanisms will be instrumental in designing new elastomers with tunable properties, as well as optimizing those currently in use.

In this study, we employ molecular dynamics simulations to determine the contributions of nanoparticulate structure, dispersion state, and interactions to the mechanical properties of filled elastomers. Specifically, we present results that probe local and global mechanical properties, providing insights into the precise spatiotemporal origins of reinforcement in the nonlinear regime. These findings offer valuable insights for the rational design and optimization of elastomeric nanocomposites with targeted mechanical properties.