Ultrafast Magic Angle Spinning F-19 NMR Study of the Bisphenol-AF Cure of Poly(Vinylidene Fluoride-Co-Hexafluoropropylene)
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 T1ρrelaxation 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.
Abstracts of Papers of the American Chemical Society
Baughman, Jessi A.; McCord, Elizabeth F.; Fox, Peter A.; and Rinaldi, Peter L., "Ultrafast Magic Angle Spinning F-19 NMR Study of the Bisphenol-AF Cure of Poly(Vinylidene Fluoride-Co-Hexafluoropropylene)" (2014). Chemistry Faculty Research. 23.