Role of Interfacial Resistance to Shear Stress on Adhesive Peel Strength

The adherence of an acrylic tape on silicone elastomers containing various quantities of a silicone MQ resin has been investigated by an instrumented peel test, along the lines of Newby and Chaudhury's work (Langmuir 1997, 13, 1805−1809; Langmuir 1998, 14, 4865−4872), which gave the first evidence of interfacial slip when a pressure-sensitive adhesive is peeled from a thin poly(dimethylsiloxane) (PDMS) layer. In the present study, we show that the amplitude of interfacial slip movements is correlated to the composition of the elastomer in MQ resin (small silica-like particles inserted into the elastomer). High slip amplitudes are associated with low MQ resin content and result in weak shear deformations in the adhesive. Thus, depending on the composition of the elastomer, the peel energy is dominated either by frictional losses associated with slip at the interface (low MQ resin content) or by viscous dissipation due to shear deformations distributed in the volume of the adhesive (high MQ resin content). ...