Theoretical Simulations of Electron-Induced Degradation of Perfluoropolyether

Abstract

Electron-induced degradation of perfluoropolyether (PFPE) was simulated by a semi-empirical molecular orbital calculation of a model using a methylene oxide segment. The calculated heat of formation of the optimized structure showed that the anion radical was more stable than the neutral molecule by 186.9 kj/mol, while the cation radical had higher energy by 1281.7 kj/mol compared with the neutral. The calculated bond order indicated that several carbon-oxygen bonds were weakened in the anion radical. The estimated activation energies for the cleavage of the weakest C-O bond of the anion radical, the cation radical, and the neutral were 68.0, 22.1 and 334.2 kj/mol, respectively, and the ion radicals were expected to decompose easily. The anion intermediate formed after the above degradation of the anion radical was suggested to successively degrade to produce carbonyl fluoride.