Prediction of Peel Adhesion using Extensional Rheometry

Abstract
If one monitors the performance of an adhesive with a 180° peel test, then the flow‐field to a good approximation is uniaxial extension at a decreasing rate. In our work a polyester adhesive was subjected to careful rheological characterization, including measurement of its extensional flow response. The response to extensional flow was used, in turn, to predict peel force using the early concepts of Gent and Petrich with excellent results. A form of the BKZ constitutive equation was also used to predict the stretching response and, in turn, the peel force. Again, very good agreement with experimental peel‐force results was obtained. The applications of extensional rheometry to the selection of adhesives are discussed.