THE DEGRADATION OF POLYTETRAFLUOROETHYLENE BY IONIZING RADIATION
Radiation effects on polytetrafluoroethylene were reinvestigated using powder and film samples placed in glass ampules which were degassed and sealed either immediately or after introduction of air or O/sub 2/. The ampules were exposed to a 4-Mev electron beam for doses of 1 x 10/sup 9/ rad each while being cooled externally with a water spray, and the gaseous products and films were analyzed by mass and infrared spectroscopy, For films irradiated in vacuum, the infrared spectrum had two bands at 982 and 1350 cm/sup -1/, while that for films irradiated in air or O/sub 2/ was identical except for additional bands associated with oxygenated structures, e.g., 1757, 3096, and 3472 cm/sup -1/. The gaseous irradiation products were examined by mass spectrometry up to mass 330, and a range of saturated fluorocarbon fragments (C/sub 1/ to C/sub 6/) was found. For irradiation in vacuum, compounds positively identified were CF/sub 4/ , C/sub 2/F/sub 6/, C/sub 3/F/sub 8/, and SiF/sub 4/. For irradiation in air or O/sub 2/, CF/sub 4/, C/sub 2/F/sub 6/, and SiF/sub 4/ were also present, but the amount of fluorocarbon fragments was smaller, and a high proportion of CF/sub 2/O was present. For irradiation in both air and vacuum, intense unidentified bands occurred in the 7.5- to 8.5- mu region. A mechanism is proposed for the formation of the irradiation products. (D.L.C.)
- Research Organization:
- Explosives Research and Development Establishment, Waltham Abbey, Essex, Eng.
- NSA Number:
- NSA-15-002663
- OSTI ID:
- 4122393
- Journal Information:
- J. Polymer Sci., Journal Name: J. Polymer Sci. Vol. Vol: 45
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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