Characterization and modeling of filled rubber submitted to thermal aging

This paper focuses on the characterization and the modeling of the behavior of butadiene rubber filled with carbon black that can be subjected to thermal aging phenomena. We consider only anaerobic thermal aging (i.e. we neglect diffusion effects) and we follow both the evolution of the behavior and that of the cross-linked network during aging with the help of mechanical and swelling tests. Based on experimental observations, we propose a fully coupled, finite strain, thermo-chemo-mechanical model that takes into account the chemo-physical evolution of the cross-linked network due to thermal aging. This model integrates a coupling between the chemo-physical evolution and the mechanical state that makes it possible to represent experimental observations. A specific strategy for the identification of material parameters is presented and provides promising results. Finite element implementation of the constitutive model is briefly described and allows to identify the chemo-mechanical coupling term from a creep test under thermal aging. (C) 2019 Elsevier Ltd. All rights reserved.