IR-spectroscopic examination of polytetrafluoroethylene and its modified forms

The results of IR-spectroscopic examinations of the molecular and supramolecular structure of polytetrafluoroethylene and polymer materials thereof were summarized. It was shown that, upon heat, mechanical, and other treatment, as well as under radiation exposure, polytetrafluoroethylene preserves its chain-helical conformation, and the resulting modified forms consist of crystalline and amorphous phases in a ratio depending on the history of the sample. The degree of the structural ordering in the polymer decreases with increasing temperature and pressure. The formation of branched moieties and short macromolecules with double bonds (−CF=CF2) in the terminal groups is specific for the process caused by thermal and radiation-induced degradation. The oxidation of the polymer macromolecules requires applying high irradiation doses and heating samples in an oxygen or air atmosphere.