Polyurethane Shear-Activated Adhesives: Effect of Counterface Chemistry

Although surface chemistry is less important in dry adhesion than surface geometry, it may still prevent reliable attachment from being established in shear-activated adhesives. However, some materials can be more universal than others in their adhesive interaction with random counterfaces. To identify a material that would be preferable for use in dry adhesives, here we studied the attachment properties of polyurethane (PU) in contact with several substrates of different chemical compositions. It was found that the pull-off and static friction forces measured with our PU-based adhesive are only moderately sensitive to the counterface chemistry, which makes PU a good material of choice for dry attachment systems. In addition, the effect of counterface roughness was clearly demonstrated to dominate over the effect of counterface chemical composition.