Adhesion between a Viscoelastic Material and a Solid Surface

In this paper, we present a qualitative analysis of the dissipative processes during the failure of the interface between a viscoelastic polymer, characterized by a weak adhesion, and a solid surface. We reassess the “viscoelastic trumpet” model (de Gennes, P.-G. C. R. Acad. Sci. Paris 1988, 307, 1949), to express the viscous energy dissipated in the bulk as a function of the rheological moduli of the material, involving the local frequencies of solicitation during crack propagation. We deduce from this integral expression the adhesion energy for different kind of materials: (i) we show that, for a cross-linked polymer, the dissipation had been underestimated at low velocities. Indeed, the interface toughness G(V) starts from a relatively low value, G0, due to local processes near the fracture tip, and rises up to a maximum of order G0(μ∞/μ0) (where μ0 and μ∞ stand for the elastic modulus of the material, respectively at low and high strain frequencies). This enhancement of fracture energy is due to far-...