Investigation of phase structure of poly(vinylidene fluoride) and characterization of its NMR fingerprints from three main polymorphs are presented by exploiting 13 C-{ 19 F, 1 H} and 19 F-{ 1 H} MAS NMR experiments. Selective excitation of 19 F NMR signal from different phases has been used for a straighforward identification and separation of spectroscopic signatures not only from the amorphous part but also from R, β, and γ polymorphs. A new insight into the phase structure of morphologically different samples has been gained by T 1F( 19 F) relaxation measurements in the conditions of very high spinning speeds and strong radio-frequency field. Motional heterogeneity of the reverse units has been revealed, and their spatial location in the amorphous, intermediate, and crystalline phases was quantified for the first time. The spectroscopic fingerprints along with phase structure features of PVF 2 and the ways exploited in this work for their retrieval might be useful to obtain structural information on PVF2 of different origin as well as on other types of fluoropolymers.

An insight into the motional heterogeneity of a series of poly(ether-block-amide) copolymers is presented and discussed in terms of its NMR fingerprints dependent on a content and length of hard and soft segments and a microphase-separated morphology. Local-field dipolar spectra carry a straightforward signature of microphase-separated morphology endowed with a strong mobility gradient. The dipolar features of the poly(tetramethylene glycol) (PTMG) and polyamide-12 (PA) components, besides visualizing the presence of separated PTMG and PA phases, also give evidence for the presence of the dynamic heterogeneity of each component. 1H MAS spectra provide an another fingerprint of phase-separated systems. Although such spectra roughly show increasing line broadening at higher PA/PTMG ratio, they are mainly sensitive to the presence of the most mobile fragments and may give a distorted vision of intrinsic mobility of the soft component in the presence of its dynamic heterogeneity. 13C spectra bearing proton−carbon J-coupling features appear to be more sensitive to the length of the soft blocks and seem to bring a proper visualization of their overall mobility. Special attention has been paid to characterize motional heterogeneity of the soft component by exploiting cross-polarization transfer efficiency combined with indirect T 2(1H) relaxation measurements. The cross-polarization inversion experiments provide, from heteronuclear dipolar interaction perspective, a corroborating visualization of the extent of motional distribution of the PTMG component. The revealed fingerprints of the motional heterogeneity of the soft component and the ways exploited in this work for their retrieval might be helpful for a better assessment of its role in the mechanical properties of thermoplastic elastomers.