Proton spin-diffusion in PVDF: a 1H–19F CP/MAS NMR study

Abstract

Proton spin-diffusion experiments were carried out in order to investigate the domain structure of semicrystalline poly(vinylidene fluoride) by means of different approaches. Besides static proton NMR experiments of the Golden–Shen type the spin-diffusion phenomenon has been studied by means of ¹H–¹⁹F NMR dual-channel cross-polarization in conjunction with magic-angle spinning. The fluorine NMR detection of proton spin-diffusion gives a much higher discrimination of the effect due to the large chemical shift differences between the signals of the crystalline and amorphous regions. Different mobility filters were applied in order to create a magnetization profile which allowed the measurement of the transfer from the crystalline regions to the mobile parts and viceversa. The data for the magnetization transfer of the spin-diffusion process support the two-component model of the polymer.