Fluorescent analysis of polytetrafluoroethylene treated by γ-irradiation near the melting point

Radiation-modified polytetrafluoroethylene (PTFE), which exhibits intense fluorescence in the visible spectral region, was prepared. Radiation modification was performed with 60Co rays at 330 °C, at a dose of 0.2 MGy and an atmospheric air pressure ranging from 10−3 to 100 mbar. The fluorescence and electronic absorption spectra of film and block PTFE specimens irradiated under the given conditions were studied. It was concluded that polyene systems of π-bonds -CF2-(CF=CF)n-CF2- (n=4-7) in the product are responsible for fluorescence. A scheme for the radiation-chemical transformation resulting in π-conjugated structures was proposed. The important role of molecular oxygen in radiation-chemical processes responsible for the generation and build-up of fluorescing entities was revealed.