Time dependence in the adhesion of viscoelastic materials

An experimental approach for studying the interfacial strength of polymer bonded composite constituents is discussed. Macroscopic spherical caps formed of filler material are pressed against half-planes of matrix material and pulled off. The experimentally measured parameters are force, contact-area and displacement. Measuring both the bonding and debonding curves provides enables the study of hysteresis in the system. Measurements performed on Sylgard 184 polydimethylsiloxane shows increasing hysteresis as the loading rate is raised, and the critical tensile load required to separate the system is observed to increase by an order of magnitude compared to that expected for a purely elastic material.