| 초록 |
NMR has long played a pivotal role in studying reaction mechanisms and kinetics in the field of polymer chemistry, since the technique reveals molecular structures and interactions with atomic resolution. In the overwhelming majority of uses, NMR is mainly applied as a steady-state method for analyzing products due to low sensitivity and low time resolution. A more direct and potentially more powerful approach to characterizing a reaction is the monitoring of species that arise as the reaction occurs. From this point of view, solid-to-liquid state dynamic nuclear Polarization (DNP) affords a large enhancement of NMR signal in small-molecules. With this signal enhancement, 13C, the nucleus carrying the most information about a polymer reaction, can be observed directly without signal averaging, despite its low gyromagnetic ratio and low natural abundance. DNP enables tracking of such reactions by NMR. In combination with the new technique that providing several orders of signal enhancement, the new method has opening a wide variety of applications in a field of polymer science. |
