Characterization of Poly(1-chloro-1-fluoroethylene) Fluoropolymer Using 1H/13C/19F Triple Resonance 3D-NMR

Ordinarily, it is possible to distinguish between mm/rr and mr/rm triad stereosequences using standard NMR experiments; however, distinction between the resonances of mm and rr triads can only be made if a spectrum from a stereoregular polymer of known relative configuration is available. This paper reports the use of a 3D 1 H/ 13 C/ 19 F triple resonance NMR experiment to unambiguously determine the resonance assignments for mm, mr/rm, and rr triad stereosequences in poly(1-chloro-1-fluoroethylene) without resorting to the preparation of stereoregular polymer having known relative configuration. Additionally, this technique provides significantly better dispersion than 1D- and 2D-NMR methods. Consequently, it was possible to completely resolve and assign 1 H, 13 C, and 19 F resonances from methylenes centered in tetrad structures and fluorine atoms centered in pentad structures.