A Review of Adhesion Mechanisms Using the Peel Test in Air and Liquid Media

Abstract

This paper deals with the analysis of peel energy of assemblies measured in different environments, i.e. in air and in the presence of liquids, and constitutes a brief review of the work of Professor Schultz' team in this domain. It is shown how such measurements can lead to a better knowledge of the nature as well as of the magnitude of fundamental interactions established at the interface between two solids. Earlier experiments have shown that peel energy can be expressed as a product of three terms corresponding, respectively, to the reversible energy of interfacial adhesion, the hysteretic losses of the bulk materials and the molecular dissipation near the crack front during peeling. This approach is well-verified when only physical interactions (van der Waals) are involved at the interface. However, more complex cases correspond to systems where specific interactions are also established between both materials, in particular acid-base interactions and creation of chemical bonds. In both cases, peel measurements in liquid media can lead to the determination of fundamental parameters, such as the interfacial density of specific interactions at the interface and the acid-base or chemical components of the work of adhesion. Finally, the effect of interdiffusion phenomena on peel energies can also be investigated in the case of elastomer/elastomer assemblies.

Key Words:

• interfacial interactions
• acid-base interactions
• dispersion interactions
• chemical interactions
• peel energy
• energy of adhesion
• surface free energy
• work of adhesion
• adhesion mechanisms
• environmental effects