The use of for new structure determination in the radiolysis of FEP

Fluorinated cotelomers based on vinylidene fluoride (VDF) and hexafluoropropene (HFP): Synthesis, dehydrofluorination and grafting by amine containing an aromatic ring

“…The presence of isomer 9 bearing (a) unsaturation was evident from the assignments of 19 F NMR signals and the coupling constants (in Table 1), as follows: two doublets of multiplets centered at À134.6 and À134.9 ppm (for fluorine atom ''x'' in cis configuration of molecules 5 and 9) and À162.6 and À163.4 ppm (for fluorine atom ''x'' in trans configuration of molecules 5 and 9) [31,54,60]; two doublets of multiplets located at À131.5 and À131.8 ppm (for fluorine atom ''v'' in cis configuration of molecules 5 and 9) and at À155.2 and À156.0 ppm (for fluorine atom ''v'' in trans configuration of molecules 5 and 9) [31,54,60]; two doublets of doublets ( 4 J CFC CF = 23 Hz) centered at À68.9 and À69.5 ppm assigned to the three fluorine atoms of CF 3 group (signal ''b'') in cis and trans configurations, respectively [54].…”

Quantum chemistry calculations of branched fluorocarbon systems

“…The studies of PTFE and its co-polymers, for example, poly(tetrafluoroethylene-co-perfluoropropylene) showed changes of properties of these materials under irradiation in various conditions. NMR studies have shown a remarkable complication of the NMR spectrum in this case [6]. The interpretation of the observed changes is traditionally made using the experimental data for molecules of similar compositions, what is not always productive and unambiguous.…”

Book Review: Molecular Modeling—Basic Principles and Applications, Second Edition. By Hans‐Dieter Höltje, Wolfgang Sippl, Didier Rognan, and Gerd Folkers.

“…The new resonances observed by these researchers were similar, and have been assigned to new –CF 2 –CF 3 chain‐ends, new –CF 3 side branches and new –CF– branch points, unsaturated links in the polymer chain, and new –CF 3 groups adjacent to unsaturated structures. Recently, we have reported7–9 19 F NMR spectroscopic studies of the γ‐radiolysis of FEP under vacuum in which we identified the major new resonances.…”

“…This utility of fluorine NMR is principally derived from the high abundance of the 19 F isotope and the relatively large range in the chemical shifts for the fluorine atoms in various chemical structures. The new structures formed on radiolysis of a number of fluoropolymers have been reported for a range of polymer environments, and we have recently reported some preliminary studies of the radiolysis of FEP 7–9. In these studies, we have used 19 F NMR spectroscopy to identify the new structures which are formed.…”