The Development of Radiation-Resistant Insulators.
Final rept. 1 Jul 66-15 Jan 72,
OAK RIDGE NATIONAL LAB TENN
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The electrical properties of capacitor insulation the critical component in ion- chamber, quartz-fiber dosimeters were related to theories of conduction and dielectric relaxation in insulators. A GENERAL SURVEY REVEALED THAT A K2S2O8- initiated, emulsion-polymerized copolymer of styrene and alpha-methyl styrene had a uniquely rapid decay of conductivity following irradiation. The decay of conductivity resulted from removal of mobile charge carriers identified as electrons or holes by a polar phase uniformly dispersed through the polymer by association with sulfate chain ends. A recipe for polymerization of a styrene homopolymer having such trapping species was optimized for moisture sensitivity and fabrication characteristics. Rapid decay was also achieved by incorporation of organic phosphites in solution-cast plastic films. It was found that acid groups methacrylic, maleic copolymerized with styrene were without effect on postirradiation conductivity. Effective trapping was produced, however, by neutraliza-tion and incorporation of water or emulsifier. This demonstrated that trapping action was not associated with a unique chemical composition but with a strongly polar phase uniformly distributed through the polymer. Author-PL
- Radiation and Nuclear Chemistry
- Radioactivity, Radioactive Wastes and Fission Products