Comparative Infrared Spectroscopy Study of Tetrafluoroethylene Telomers Exposed to Gamma Radiation in Air and in a Vacuum

Five samples of tetrafluoroethylene (TFE) telomers in carbon tetrachloride (CCl4) were obtained by radiation-initiated telomerization. The initial TFE concentrations in CCl4 (Ci) were 1.82, 4.3, 6.5, 17.8, and 20.6 wt %. It has been found that the main difference of the IR spectra of the synthesized telomers from the IR spectrum of polytetrafluoroethylene is the presence of an absorption band of CCl3 terminal groups at 850 cm−1, the intensity of which (I850) increases with a decrease in Ci. It has been shown that the dependence of I850 on Ci is satisfactorily described by a fractional rational function. The dry telomers have been irradiated with 60Co γ-rays with a total dose of 1020 kGy both in air and in a vacuum. A detailed analysis of the IR spectra of the irradiated samples has shown that a transformation or cleavage of the –CCl3 terminal groups occurs in a vacuum. In the case of irradiation of the telomers in air, the formation of carboxyl (–COOH) groups is observed in addition to the above event. If the stability of the telomer is associated with the formation of –COOH groups, then the stability increases with an increase in Ci for the studied set of telomers.