Fluorine-19 MAS and H-1 -> F-19 CP/MAS NMR studies of Viton fluoropolymers

Fluorine-19{H-1} nuclear magnetic resonance (NMR) at 188.29 MHz including H -1 --> F-19{H-1} cross-polarization (CP) with high-speed magic-angle spinni ng (MAS), was used to study some fluoropolymers of the Viton type. The syst ems examined were (a) copolymers of vinylidene fluoride and hexafluoroprope ne and (b) terpolymers of vinylidene fluoride, tetrafluoroethene and hexafl uoropropene. Both commercial and specially prepared samples were used. Diff erent H-1 --> F-19{H-1} CP/MAS experiments were applied to study the relaxa tion of the polymers. The results are discussed in terms of the CP dynamics , using parametrized equations. (C) 1998 John Whey & Sons, Ltd.