Effects of Moisture Absorption on the Mechanical Properties of Adhesives with Viscoelastic-Plastic Deformation Behaviour

摘要

A new test procedure to investigate the effect of water uptake on the mechanical properties of a structural epoxy adhesive is presented. By means of Dynamic Mechanical Analysis (DMA) changes in the viscoelastic properties of tensile bulk specimens due to water diffusion are recorded during isothermal tests at 29 °C under laboratory conditions and subsequently immersed in distilled water. A correlation between the diffusion rate and the change of the storage modulus (E') and loss Modulus (E") of the adhesive was found. Furthermore this method describes a new approach to separate reversible and irreversible changes due to the absorption of liquids into polymer networks.