4.4. Adhesion Testing

Polymer-polymer adhesion experiments were performed with a force-calibrated custom fixture designed for the TA-XT plus with 50 kg load cell (Stable Micro Systems, Godalming, Surrey, UK, Figure 1). The fixture was composed of a 30 mm diameter flat-ended cylindrical probe and a flat fixture surface designed with vacuum fixation. The films were attached to polychloroprene mount using proprietary 3M adhesive (3M, St. Paul, MN, USA) or cyanoacrylate adhesive (VetBond, 3M, St. Paul, MN, USA). The cylindrical probe compressed the two polymers followed by the separation of the probe from the surface by an applied tensile load. The radius of contact was defined as the radius of the probe (a) and the thickness of the contacted polymers was h. The pre- and post-experimental geometries were nearly equivalent for large values of a/h with minimal evidence of edge effects. Probe velocity, compression force and distance were recorded at 500 pps. A minimum of N = 10 films per data point were tested.