| 초록 |
Solid-state NMR spectroscopy is a powerful technique that has been utilized in investigating the molecular mobility on a microscopic scale. Solid-state NMR relaxation studies can reveal details of molecular motion (i.e., chain mobility). To study of the side-chain mobility of comb-like fluorinated polystyrenes with different side chain interconnecting groups between backbone and side chain, such as ether (PST-O), thioether (PST-S) and sulfone (PST-SO2), were examined by solid-state 19F NMR spectroscopy. To get information about average local side-chain motion, measurements of spin-lattice relaxation time in the laboratory frame (T1) and in the rotating frame (T1ρ) over the temperature range 200-370 K were made. Then, the corresponding correlation times, τc’s, were determined from fitting the relaxation data based on Bloembergen-Purcell-Pound (BPP) theory, and the activation energies, Ea’s, obeying the Arrhenius relation with τc, were accordingly obtained. |
