STUDIES ON OXIDATIVE PHOTODEGRADATION OF EPOXY-RESINS BY IR-ATR SPECTROSCOPY

This article describes studies on oxidative-photodegradation of cured Epolite epoxy resin using techniques of IR spectroscopy with attenuate d total reflectance optics and scanning electron microscopy. The resul ts show that the oxidative-photodegradation of this epoxy system is ch aracterized by the formation and subsequent decomposition of carbonyl groups and by epoxy ring opening. The carbonyl bonds are apparently fo rmed in the initial stage of photodegradation and then decomposed upon further aging. Changes in the surface morphology of the samples durin g degradation suggest that there is significant scissioning of the cro ss-linked polymer structure. This phenomenon was reproduced using thre e different UV lamps that differed in spectral properties. Our studies provide clues to the mechanism of epoxy polymer degradation by solar light. (C) 1994 John Wiley & Sons, Inc.