Polystyrene Solutions: Characterization of Molecular Motional Modes by Spectrally Resolved Low‐ and High‐Field NMR Relaxation

Polystyrene solutions in CDCl3 were examined by different NMR techniques. Diffusion measurements and spectrally resolved frequency-dependent 1H longitudinal relaxation studies give some insight into the complex molecular motional modes and their frequency dependence, that is, the dispersion of the longitudinal relaxation rate. The newly available spectral resolution at low magnetic field around 20 MHz 1H-Larmor frequency additionally allows the differentiation of aliphatic and aromatic spectral contributions and, therefore, a more detailed description of the molecular mobility in the frequency range of several MHz compared to the well-known time-domain or field-cycling NMR studies.