ABSTRACT
Liquid uptake of polymers, especially of elastomers, is associated with swelling. The swelling process is induced by diffusion and causes stresses, which interact with the diffusion again. Thus, swelling is a coupled phenomenon of mechanical behaviour and mass transport. The material behaviour of a swelling elastomer is investigated by experiments referring to the equilibrium state of swelling, when the liquid concentration in the elastomer reaches a saturation level. Following established viscoelastic material models for large deformations, a split into equilibrium and viscose part is common. Both parts are influenced by the resence of fluid. This influence is the focus of this paper by using a typical experimental set up to determine material parameters. Furthermore, experiments show that swelling depends on the externally applied stress. This effect leads to the discussion if the presented well-established experimental set up is usable to determine viscoelastic material parameters. In this context it is pointed out, that the usability of the experiments depends on the time scale of the adoption.
