Relationship between the fracture energy and the mechanical behaviour of pressure-sensitive adhesives

Abstract : Mechanical behaviours of two pressure-sensitive adhesives (PSAs) families, composed of elastomer copolymers or polyacrylate/acrylic copolymers, are characterised by peel tests. Fracture energy varies linearly according to the applied contact force between two levels, which depends on tackiness and cohesion of the PSA. Local fracture energies are measured by an original peeling system and they are related with the adhesive deformation. Mechanical behaviours of PSAs depend on their composition but majority of fracture energy is dissipated on the first millimetre near the bending zone where fibrils elongation is maximum. Observations of interfaces between PSAs and glass substrate underline that fracture energy varies linearly according to the contact area.