Abstract
The ESR spectrum of the radicals formed by the reaction of oxygen with γ-irradiated polytetrafluoroethylene (PTFE) has been obtained using oxygen isotopically labeled with 17O. The presence of lines from two oxygen nuclei both labeled with 17O confirms that peroxy radicals are formed. Two types of peroxy radicals are discussed; firstly, the peroxy chain radical (–CF2–CF(O1Ȯ2)–CF2) with g⊥=2.0220, g∥=2.0060, a∥(1) =40±1 G, a∥(2) =89±1 G at 300 K, and gzz=2.0380, gyy=2.0065, gxx=2.0026, axx(1) =46±1 G, axx(2) =107±1 G at 77 K and secondly, the peroxy propagating radical (–CF2–CF2(O1Ȯ2)) with giso=2.004, aiso(1) =13±1 G, aiso(2) =26.5±1 G at 300 K and identical parameters to the peroxy chain radical at 77 K. The temperature dependence of the ESR spectra is analyzed in terms of the rotational freedom in the polymer. The peroxy chain radical undergoes rotation along the polymer chain axis and the peroxy propagating radical also has this rotation about the chain axis and in addition rotates about the C–O bond which is nearly perpendicular to the main chain axis.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
