Electron spin resonance studies of free radical decay in gamma‐irradiated polyethylene

Publisher Website
Google Scholar
Abstract
Polyethylene was irradiated in vacuo at liquid nitrogen temperature and allowed to warm up. The concentration of free radicals, as observed by electron spin resonance (ESR) spectroscopy, decays very quickly to a relatively stable value which is temperature dependent. This behavior is interpreted to mean that these reactive radicals are relatively close to one another as opposed to random distribution. The cold‐irradiated sample was exposed to air, and the formation of the peroxy radical was observed at −80°C. Only 40–45% of the radicals reacted. This was interpreted to mean that 90–95% of the radicals trapped at −195°C. are in the amorphous phase