Accession Number : AD0698051

Title :   ESR SPECTRA OF ORIENTED POLYTETRAFLUOROETHYLENE SUBJECTED TO 20-nsec PULSES OF ELECTRONS,

Corporate Author : LOCKHEED MISSILES AND SPACE CO PALO ALTO CALIF LOCKHEED RESEARCH LAB

Personal Author(s) : Lerner,N. R.

Report Date : 14 MAR 1968

Pagination or Media Count : 9

Abstract : Samples of oriented polytetrafluoroethylene have been subjected to irradiation from a pulsed electron beam generator. The duration of the pulses was 20 nsec, and doses ranging from 0.8-14 Mrad were delivered to the samples. Working with oriented samples makes it possible to distinguish and identify two distinct species in the samples irradiated in air. The relative concentration of the two species varies as a function of the dose. In samples receiving larger doses of radiation the species -CF2-(CF-O-O)-CF2-dominates the ESR spectrum. At lower doses the species -CF2-O-O. makes a larger relative contribution to the ESR spectrum. Samples were also subjected to irradiation in vacuum. The ESR spectra obtained from the vacuum-irradiated samples before and after the admission of air is discussed. Samples were subjected (in air) to radiation from a 60Co source, ranging from 5-30 Mrad, at a dose rate of 0.43 Mrad/h. The species -CF2-O-O. dominates the ESR spectrum of 60Co irradiated samples. The details of the line shapes of the ESR spectra of samples irradiated in air are discussed. (Author)

Descriptors :   (*HALOCARBON PLASTICS, *ELECTRON PARAMAGNETIC RESONANCE), (*ELECTRON IRRADIATION, HALOCARBON PLASTICS), (*RADIATION CHEMISTRY, HALOCARBON PLASTICS), DEGRADATION, FREE RADICALS, FLUORINE COMPOUNDS, OXIDATION, OXYGEN

Subject Categories : Radiation and Nuclear Chemistry
      Plastics

Distribution Statement : APPROVED FOR PUBLIC RELEASE