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

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 Golde n-Shen type the spin-diffusion phenomenon has been studied by means of H-1- F-19 NMR dual-channel cross-polarization in conjunction with magic-angle sp inning. The fluorine NMR detection of proton spin-diffusion gives a much hi gher discrimination of the effect due to the large chemical shift differenc es between the signals of the crystalline and amorphous regions. Different mobility filters were applied in order to create a magnetization profile wh ich allowed the measurement of the transfer from the crystalline regions to the mobile parts and vice versa. The data for the magnetization transfer o f the spin-diffusion process support the two-component model of the polymer .