Abstract
The fluorination polyethylene treated by fluorine-containing gas (F2 concentration 10%, 10h, at room temperature) showed good heat oxidation resistance values. When a partial discharge of 10 hours was applied to the fluorinated polyethylene, no formation of carbonyl groups nor any weight-loss was observed, indicating that the fluorine gas treatment improved the partial discharge resistance by six times compared with untreated polyethylene. The chemical shift in bonding energy during the fluorination is discussed based on ESCA measurements. The fluorine content in the treated polymer was found to be controllable effectively with gas concentration, time and temperature in fluorination. Thus the present fluorination treatment of the polyethylene powder may provide a polymer suitable for the cable coating which is resistant against the partial discharge, but has mechanical stiffness like that of untreated polyethylene. The partial discharge resistance was interrelated to the crystallinity of the polymer analyzed from the X-ray diffraction and infrared absorption methods.
