Electron beam induced degradation of polyperfluorinated ethers: -(CF(CF₃)-CF₂-O)_n-, for n = 4, 8 and 50

Polyperfluorinated propylene oxides, -(CF(CF3)-CF2O-)n-, where n = 4, 8 and 50, are exposed to electron beams and their subsequent degradation monitored via infrared spectroscopy at T = 11 and 298 K. COF2, CF4, and R-CFO are produced and their G values are reported as a function of n, the number of monomer units, in the polymer. The G values range from 0.1 to 3, depending upon the gas product and n. The efficiency for gas evolution decreases with increasing number of monomer units. For n = 4, R-CFO, CF4 and COF2 are produced with G values of 3.0, 2.7, and 2.4, respectively. As n increases to 50, COF2 becomes the dominant product with a G value of 1.0, followed by CF4 at 0.7, and R-CFO at 0.1.