THE RADIATION-CHEMISTRY OF PERFLUORINATED ETHERS

The investigation on the radiation chemistry of the perfluoropolyether s carried on through the analysis of the free radicals intermediates, of the structural changes in the oligomers chains and with the support of M.O. calculations has afforded information on the major features o f the mechanism of radiolysis, The main radiolytic process is chain de gradation by C-C and C-O bond rupture. Evidence of a minor participati on of C-F bond scissions have been obtained in the case of poly(perflu orotrimethylene oxide) PF3MO and poly(perfluoroethylene-perfluoromethy lene oxide) PFEMO. The nature of the radicals intermediates and the st ructure of the novel units produced in the oligomer chains fit a radio lysis mechanism where both the ionic and excitation paths seem to be o perative giving rise to complex sequence of radical reactions. The str ucture and possible reaction modes of the molecular cation and anion r adicals are discussed on the basis of PM3 semi-empirical M.O. calculat ions.