Bonding of silicone rubbers on metal (2) physical chemistry of adhesion

In the previous paper of this series, three primer formulations were tested for the adhesion of two different grades of silicone elastomer on aluminum studs. The simple approach consisting at analyzing primers' chemical composition was not suitable to generate a formulation allowing “universal” adhesion of silicone elastomer on metal. In the second part of this series, we studied more specifically the properties of the primer films (topology, thickness and roughness, surface energy) and of the primer/silicone elastomer interphases after peeling test (hardness, profilometry of the fracture profile). A final discussion stresses on the parameters which govern the selectivity of a silane-based primer formulation for any type of HCR rubbers on metals.