Viscoelastic Properties of Soft Adhesives

In this paper the viscoelastic behavior of different soft adhesives with substantially similar adhesive performance is analyzed in the light of a Slip-Tube Model. In this model, the junction points between network chains and virtual chains are replaced by slip-links attached to fluctuating ends of virtual chains. The slip-links are allowed to slide along the contour of the network chains but not pass through each other. The predictions of the slip-tube model are in excellent agreement with the experimental data on uniaxial deformation of soft adhesive networks. Furthermore, the study shows that some adhesive performances can be described qualitatively by Small Amplitude Oscillatory Shear (SAOS), and the in-service properties can be described with adhesives with different viscoelastic spectra. Highly nonlinear uniaxial stretching tests reveal deeper insights into the description of the adhesives performances. Some well-established models are adopted and slightly modified by introducing the rate-dependence of their physical parameters to describe the response of soft adhesive to stretching.