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 degrada tion monitored via infrared spectroscopy at T = 11 and 298 K. COF2, CF 4, and R-CFO are produced and their G values are reported as a functio n of n, the number of monomer units, in the polymer. The G values rang e from 0.1 to 3, depending upon the gas product and n. The efficiency for gas evolution decreases with increasing number of monomer units. F or 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, COF, becomes the dominant product with a G value of 1.0, followed by CF4 at 0.7, and R-CFO at 0 .1.