ANISOTROPY OF HYPERFINE SPLITTING IN ELECTRON PARAMAGNETIC RESONANCE SPECTRA OF IRRADIATED ORIENTED POLYMERS (in Russian)
Radicals forming on the irradiation of polymers were identified by the hyperfine structure of the epr spectrum. Experiments were made by stretching oriented polymers. The epr spectra were taken at various angles between orientation of the polymer and the magnetic field at 9000 Mc/sec in the high- frequency modulated magnetic field. The investigntion covered low-pressure polyethylene stretched in the cold state; polytetrafluoroethylene (Teflon), stretched at 300 deg C; polyvinyl chloride stretched at 72 deg C; and polymethylmethacrylate stretched at 140 deg C. Irradiation took place either in the reactor (in evacuated quartz ampules at 40 to 50 deg C) or by beta radiation from a Au/sup 1//sup 9//sup 8/ needle (half life 64.6 hr). It is shown that the intensities of the lines and their number depend, in polyethylene, on the angle between elongation axis and magnetic field direction. This result is discussed on the basis of the formation of an alkyl radical. Data confirm the formation of an alkyl radical on irradiation at 77 deg K. Polyethylene irradiated at 40 to 50 deg C gave an epr spectrum with 7 components, each being a doublet. This spectrum corresponds to a uniform interaction of an unpaired electron with 6 protons. This is believed to point to the formation of an alkyl radical. Anisotropy was likewise observed in oriented Teflon; the spectra,, however, were not analyzed. No anisotropy was observed with polyvinyl chloride and polyamide. The absence of anisotropy in polymethylmethacrylate and polystyrene is explained by the fact that there is no proton in the immediate vicinity of the unpaired electron, that might cause, as with polyethylene, an anisotropy of hyperfine splitting. (auth)
- Research Organization:
- Originating Research Org. not identified
- NSA Number:
- NSA-15-021222
- OSTI ID:
- 4050988
- Journal Information:
- Vysokomolekulyarnye Soedineniya, Journal Name: Vysokomolekulyarnye Soedineniya Vol. Vol: 2
- Country of Publication:
- Country unknown/Code not available
- Language:
- Russian
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Related Subjects
AMIDES
ANGULAR DISTRIBUTION
ANISOTROPY
BETA PARTICLES
CHLORIDES
DEFORMATION
ELECTRONS
EXPANSION
FLUORINATED HYDROCARBONS
FREE RADICALS
GOLD 198
HYPERFINE STRUCTURE
IRRADIATION
MAGNETIC FIELDS
MAGNETIC RESONANCE
METALS, CERAMICS, AND OTHER MATERIALS
MODULATION
POLYAMIDES
POLYETHYLENES
POLYMERS
POLYVINYLS
RADIATION EFFECTS
REACTORS
TEFLON
VACUUM