Polymer-Aluminium Adhesion II. Role of the Adhesive and Cohesive Properties of the Polymer

The study of the adhesive strength of model elastomer/treated aluminium assemblies has led us to propose a new model of the adhesion of viscoelastic materials. In this model the energy of separation of an assembly is described by a product of three terms: —the reversible energy of adhesion or cohesion —a macroscopic dissipation factor due to viscoelastic losses —a molecular dissipation factor related to the degree of cross linking of the elastomer. This new approach allows us to explain the wide range of strengths observed depending on the nature of the surface treatment of the metal substrate. It is suggested that these large differences are essentially due to a variation of the degree of cross linking of the elastomer in the vicinity of the interface.