Effect of hostile environments on adhesive joints: IV. dynamic testing

Abstract

A rapid test procedure has been devised for determining the effect of environment on the mechanical properties of polymeric materials and on the strength of adhesive joints. The adverse effect of water on aluminium‐epoxide joints has been confirmed, but the effect has been shown to be due to a stress‐hydrolysis of primary chemical bonds rather than interference with hydrogen bonding. The use of scanning electron microscopy has shown that joints tested in dry conditions fail in adhesion, while those tested in aqueous environments fail within a boundary layer. The presence of high concentrations of an electrolyte retards the ingress of water into an epoxide polymer, and reduces the disruptive effect of water on aluminium‐epoxide joints.