Coupled analysis on hyper-viscoelastic mechanical behavior and macromolecular network alteration of rubber during thermo-oxidative aging process

• Published in: Polymer (Guilford) Vol. 171; pp. 15 - 24
• Main Authors: Zhi, Jieying, Wang, Qinglin, Zhang, Mengjie, Zhou, Zhenze, Liu, Anna, Jia, Yuxi
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 08.05.2019; Elsevier BV
• Subjects: Aging; Butadiene; Computer simulation; Constitutive models; Crosslinking; Deformation; Deformation mechanisms; Finite element method; Macromolecules; Mathematical analysis; Mathematical models; Mechanical properties; Mechanical tests; Model accuracy; Network alteration; NMR; Nuclear magnetic resonance; Rubber; Styrene; Thermo-oxidative aging; Viscoelasticity; Viscoelasticity; Thermo-oxidative aging; Network alteration
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2019.03.029

This paper synergistically addressed the microstructure alteration and the mechanical behavior of rubber during thermo-oxidative aging process from both experimental and numerical modeling aspects. Through the FTIR spectra analysis, equilibrium swelling experiment, low-field NMR measurement and mechanical tests of styrene-butadiene rubber (SBR) samples, a macromolecular network alteration mechanism was introduced. The mechanism is related to the variation of the crosslinking network and dangling chain ends of SBR during aging. A finite deformation based hyper-viscoelastic constitutive model was then established to capture the mechanical behavior of SBR during aging. Based on the interpretation of the microscopic mechanism, the above-mentioned network alterations during aging were considered in the model. After the implementation by means of the finite element simulation software ABAQUS, the accuracy of the established model was checked via the comparison of the numerical results with the corresponding data obtained from mechanical tests. The work is helpful for estimating rubber mechanical performance during aging process. [Display omitted] •A macromolecular alteration mechanism relating to crosslink network and dangling chain ends during SBR aging was proposed.•A hyper-viscoelastic constitutive model relating to the observed microscopic mechanism of SBR aging was established.•Helmholtz free energy was decomposed into the equilibrium and the non-equilibrium part, respectively.•The numerical model was implemented through the finite element method and the accuracy of the model was verified.