Using Self-Assembled Monolayers to Explore the Relationships Between Interfacial Interactions and Fracture in Structural Adhesive Joints

摘要

A problem of longstanding interest in adhesion science is to understand the relationship between the nature and spatial distribution of fundamental interfacial interactions and engineering fracture quantities such as fracture stress or fracture toughness. These relationships depend strongly on the mechanical properties of the adhesive, and in this work we focus on highly crosslinked structural adhesives. These relationships are clearly important from the standpoint of designing interfacial chemistry sufficient to provide the level of mechanical strength required for a particular application. However, this can depend greatly upon the loading conditions. In some cases, loading conditions may force cracks to initiate or propagate along a bimaterial interface even when the interfacial chemistry is robust. For other loading conditions, the location of crack initiation can shift away from the interface with only a very low level of interface strength.