On the evolution of the viscoelastic properties and their microstructural origin in a filled NBR under coupled thermal and cyclic mechanical loadings

International audienceThis study deals with the effects of coupled thermal and cyclic mechanical loadings on the viscoelastic response of carbon black filled nitrile rubber. For this purpose, cyclic loading tests were performed at different temperatures by means of DMTA. The type and level of the thermomechanical loadings applied were chosen in order to determine the relative contribution of each of the mechanical and thermal loadings (and their coupling) to the viscoelastic response during the cyclic tests. XPS and FTIR analyses were used to track the change in the microstructure corresponding to the evolution in the viscoelastic response. Results show that the storage modulus increases with the number of cycles, due to the crosslink increase, and that temperature amplifies this phenomenon. The main result is that the cyclic mechanical loading significantly amplifies the effect of temperature