Epoxy-amine reticulates observed by infrared spectrometry. II. Modifications of structure and of hydration abilities after irradiation in a dry atmosphere

This article is part of a series of articles devoted to the study of the re sponsibilities of both humidity and irradiation in the aging process of ami ne-cured epoxy resins. The basic technique used in this study is infrared s pectrometry. In a previous article we have observed, with this technique, h ydration of two kinds of epoxy resins, which are widely used in the nuclear industry. In this article the same technique is used to observe the same r esins, which have been previously submitted to ionizing radiations. It allo ws us to determine the effects these radiations have on these resins at mol ecular level and how they consequently modify their hydration mechanisms. I t could thus be established that irradiation by electrons almost does not i nduce modifications on resins cured with aromatic diamines, which results i n their hydration capacity being only slightly changed. Irradiation by gamm a rays induces stronger modifications, which reflect themselves in a greate r capacity of absorption of water and different ways of fixing H2O molecule s. Epoxy resins cured with alkyl diamines are more sensitive to irradiation and, after it, absorb a greater amount of H2O molecules. After irradiation , steric conditions, which hinder H2O molecules to bind on other H2O molecu les, apparently become less severe. (C) 2000 John Wiley & Sons, Inc.