RADIATION-INDUCED CONDUCTIVITY OF POLYMERS AT HIGH-TEMPERATURES

The radiation induced conductivity (RC) of polystyrene (PS), poly (eth ylene terephthalate) (PETP), high density polyethylene (HDPE), polytet rafluoroethylene (PTFE) and polypropylene (PP) upon continuous irradia tion by fast electrons (60 keV, a dose rate of 3 - 2 x 10(3) Gy/s) in vacuum at room and elevated temperatures was investigated. At high tem peratures, the mobility of macromolecules dramatically increased. As a rule, an RC increase was observed (with the exception of PETP where t he RC was constant up to 423 K). In the case of HDPE and PTFE, the gem inate mechanism of RC was replaced by a free-ion one. The PP retained the geminate mechanism even at 403 K although the conductivity increas ed 10 times. The data obtained are interpreted in terms of the Rose-Fo wler-Weissberg theory.