SPECTRAL PARAMETERS FOR QUANTITATIVE MOBILITY CONTRAST IN NMR IMAGINGOF SOLID POLYMERS

Different procedures based on parameters of the wideline NMR absorptio n spectrum are presented to obtain localized molecular mobility contra st for imaging of solid polymers. For this purpose a H-1-NMR imaging t echnique with magic sandwich echoes is used for acquiring localized wi deline spectra. With samples composed of polystyrene and high impact s trength polystyrene, and polycarbonate and low density polyethylene a spatial difference in NMR absorption spectrum lineshape and linewidth is displayed. Furthermore, the spatial distribution of rigid and mobil e domains in a heterogeneous polymer can be derived from the NMR spect ral components. It is demonstrated that a van Vleck moment analysis ca n be performed from spatially resolved magic echo decays. The second ( M(2)) and fourth (M(4)) moments of the rigid components show considera ble variation with the spatial composition of the investigated samples .