Hygrothermal Properties of Highly Toughened Epoxy Adhesives

The absorption and desorption of water in two different rubber-toughened epoxy adhesives was measured gravimetrically over a relatively wide range of temperature and relative humidity (RH). The data were fitted to a new diffusion model in which Fick's law was assumed to act in two sequential stages, each with its own diffusion coefficient and saturated water concentration. This “sequential dual Fickian” (SDF) model and a Langmuir-type diffusion...