Résumé : |
Water permeation, water absorption, d.c. resistance, and electrochemical impedance spectroscopy (ElS) measurements were performed on films of epoxy-polyamide used as binder in paint formulations. Barrier properties were found to be highly dependent upon the thickness of films. In thick films, water permeation measurements revealed the presence of pathways attributed to frozen holes, through which the flow is not governed by diffusion. In thin films, the presence of pinholes was detected by d.c. resistance and ElS measurements. |