Ultrafast magic angle spinning (UF-MAS, 60 kHz) solid-state 19F NMR methods at 706 MHz have been used to characterize cross-linking structures in a copolymer of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) and its curing with bisphenol-AF. Assignment of 19F resonances for the monomer and inverted monomer sequences were identified for various stages of the curing process. Additional CF3 and CF2 resonances after cross-linking corroborate the presence of previously reported cross-linking structures. Measurement of T1 and T1?relaxation times confirmed the formation of fluorine ion in the form of CaF2 during press and post cure. The data suggests rapid cross-linking occurs during the short press cure and continues at a reduced rate over the longer post cure- resulting in increased rigidity.   Figure 1. 705 MHz 19F{1H} 1D-NMR Hahn echo spectra of (a) neat poly(VDF-co-HFP), (b) polymer with additives, (c) press cured polymer, and (d) post cured polymer. Inset: The bisphenol AF region from -56 to -66 ppm magnified at 300X vertical scale.

Ultrafast magic angle spinning <sup>19</sup>F NMR study of the bisphenol-AF cure of poly(vinylidene fluoride-co-hexafluoropropylene)

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Ultrafast magic angle spinning 19F NMR study of the bisphenol-AF cure of poly(vinylidene fluoride-co-hexafluoropropylene)

Ultrafast magic angle spinning ¹⁹F NMR study of the bisphenol-AF cure of poly(vinylidene fluoride-co-hexafluoropropylene)