,-.,

Irradiation of poly(vinylethylether) thin films (thickness about 3 {lm) on KBr windows, causes the following changes of the IR spectra of the samples (23): in the region 3800-3000 cm-I : a broad band, with an absorption maximum at 3400 cm-I appears and increases. In the region of the spectrum corresponding to the C-R-stretching vibrations, photooxidation leads to the decrease of the initial bands at 2974,2941,2931, and 2869 cm-I , assigned on the basis of the literature data to the methyl and methylene groups (22). In the carbonyl region, a band with an absorption maximum at 1735 cm-I develops and a shoulder at about 1725 cm-1 is observed for longer irradiation times (Fig. 5).