Evaluation of temperature-dependent adhesive performance via combinatorial probe tack measurements

We describe the design and application of a temperature gradient probe tack apparatus for investigating the adhesive performance of model pressure-sensitive adhesives (PSAs). In particular, we illustrate a probe tack apparatus for studying the effect of temperature on three critical adhesion identifiers: adhesion energy, elongation at break, and debonding mechanisms. The measurement temperature is varied across the PSA film using a gradient temperature stage constructed from a transparent sapphire plate with a heating and cooling source positioned at opposite ends. The transparent substrate allows visualization of the contact area and debonding mechanisms during the test. The gradient temperature stage is integrated onto a motorized x-y stage, enabling a matrix of probe tack tests to be conducted across the PSA film at different sample temperatures. We use a spherical probe to evaluate the adhesive performance of a 150 mu m thick model poly(styrene-b-isoprene-b-styrene) PSA film between a temperature range of 10 degrees C to 100 degrees C. We demonstrate that this apparatus is a viable combinatorial design for tack measurements and may be extended to more complicated two-dimensional gradient films.