In situ ESR investigations of synchrotron radiation-induced degradations of polymers

While simultaneously irradiating polymers with synchrotron radiation and re cording ESR spectra, we were able to observe in situ the degradation of pol ymers and copolymers, such as poly(L-lactide-co-glycolide 10%). The experim ents reveal the formation of long-lived macroradicals, which in the case of the lactide polymer can be attributed to a molecular structure consistent with conclusions drawn before based upon the results of other analytical me thods. In order to provide measurements at least down to 100 K, a low tempe rature extension is under construction, This new combination of synchrotron radiation and ESR spectroscopy represents a powerful device for in situ in vestigations of the behavior of polymers under X-ray exposure. (C) 1999 Els evier Science Ltd. All rights reserved.