Investigation of the moisture-desorption characteristics of epoxy resin

Moisture-diffusion characteristics, which include weight changes, hygrothenrially induced expansion, diffusion coefficients, and activation energy, have been investigated for epoxy resins. The experimental results show that hygroscopic swelling behavior of the epoxy system is consistent; it increases with temperature and decreases sharply at approximately 135 degrees C. Desorption from high moisture saturation tended to leave a small residual moisture content which could be removed only by heating at relatively high desorption temperatures. Further interpretation of this phenomenon are discussed on the basis of experimental results and molecular dynamics (MD) simulations.