Coupled analysis on heterogeneous oxidative aging and viscoelastic performance of rubber based on multi-scale simulation

An oxidative aging-viscoelastic constitutive model was established to study the coupled heterogeneous oxidation and viscoelastic performance of rubber during aging process. The basic elasticity and viscoelasticity of rubber materials were comparatively considered as the function of ongoing aging. The dynamic compression process of natural rubber at different aging times was analyzed by the finite element method. And then the effects of oxygen uptake, diffusion, and oxidative reactions on the dynamic viscoelasticity of rubber were analyzed. The permeability of the oxygen in natural rubber was determined by means of molecular dynamics simulation. The results reveal that the heterogeneous degradation caused by diffusion-limited oxidation can lead to a complex stress distribution in the natural rubber specimen under dynamic loading condition; the relaxation time and the energy dissipation of the rubber specimen also increased after aging. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47452