High-Resolution Variable-Temperature MAS ¹⁹F NMR Spectroscopy of Fluorocarbon Polymers

Temperature Calibration under Ultrafast MAS Conditions

“…In the latter case, the interpretation of the 1 H spectra is only possible at these ultrafast MAS frequencies. Moreover, in 19 F NMR, ultrafast MAS achieves both dipolar decoupling and averaging of the chemical shift anisotropy, thus yielding high-resolution spectra, as has been shown for inorganic fluorides (6) and fluoropolymers (7,8). Additionally, such high MAS frequencies have been used to simplify 23 Na and 27 Al multiple-quantum (MQ) MAS spectra by the effective removal of heteronuclear dipolar couplings, such that the origin of the observed MQ MAS spinningsideband patterns (9, 10) in first-order quadrupolar systems is more easily elucidated (11).…”

Analysis of Cross-Polarization Dynamics between Two Abundant Nuclei, 19F and 1H, Based on Spin Thermodynamics Theory

“…Figure FIG. 8 shows a H-H matching profile measured by 1 H 3 19 F CP MAS under the same conditions as above. Solid-state 1 H 3 19 F CP MAS spectrum of the 6FDA/ODA polyimide measured under the Hartmann-Hahn condition.…”

“…High-speed magic-angle spinning and high-power decoupling techniques facilitate the measurement of high-resolution solid-state 19 F NMR spectra for proton-containing fluoroorganic compounds and fluoropolymers (1)(2)(3)(4)(5)(6)(7)(8)(9). The 100% natural abundance, the large magnetogyric ratio, and the large chemical shift range of this nucleus are great advantages for its NMR observation.…”

High-Resolution Variable-Temperature 19F MAS NMR Spectroscopy of Vinylidene Fluoride Based Fluoropolymers

“…21 Copolymer C and the compound previously published are both copolymers of VF 2 and chlorotrifluoroethylene (CTFE) with similar monomer feed ratios (Table 1). In this publication we present our results when copolymer C is analyzed with 64 transients at 250°C and 22 kHz MAS and acquired with 3072 data points, as shown in Figure 5 and Table 4.…”