Peeling of acrylic pressure sensitive adhesives: Cross-linked versus uncross-linked adhesives

In this paper we analyze the adhesive properties of two kinds of adhesives, determined by a 90 degrees peeling test on a Pyrex(TM) substrate. Simultaneously, we observe the mechanisms of flow at the peeling front. An uncross-linked acrylic pressure-sensitive adhesive is used, whereas the second one, of the same class, is slightly cross-linked. The mechanisms of peeling are compared with the ones of our previous study (Benyahia et al. [8]) and are found to be identical in the case of uncross-linked adhesives. On the other hand, we find new regimes of Row when the adhesive is cross-linked. To investigate these differences further, we determine the rheometrical properties of the adhesives in dynamic shear tests and in uniaxial elongational experiments. Furthermore, surfaces are characterized. A discussion of the reeling curves is finally presented, showing the combined effects of the rheological properties and the surface ones. Conditions for predicting the type of regimes and transitions are also investigated.