摘要
^(13)C-NMR ~1H-decoupled spectra of styrene polymers were assigned by comparison with modelcompounds, then used in measurements of number average molecular weights. The higher limit of an exactdetermination of the end group signal is less than a molecular weight of 10~4. For polymer samples withM_n<10~3, the results obtained from ^(13)C-NMR spectra of saturated carbon region are in excellent agreementwith the values determined by ~1H-NMR, SEC, and VPO methods, while the results from ^(13)C-NMR spectra ofphenyl C-1 carbon region are somewhat higher than the values determined by other methods.
^(13)C-NMR ~1H-decoupled spectra of styrene polymers were assigned by comparison with modelcompounds, then used in measurements of number average molecular weights. The higher limit of an exactdetermination of the end group signal is less than a molecular weight of 10~4. For polymer samples withM_n<10~3, the results obtained from ^(13)C-NMR spectra of saturated carbon region are in excellent agreementwith the values determined by ~1H-NMR, SEC, and VPO methods, while the results from ^(13)C-NMR spectra ofphenyl C-1 carbon region are somewhat higher than the values determined by other methods.
基金
The Project is supported by the Chinese National Basic Research Project"Macromolecular Condensed State"and the National Natural Science Foundation of China.
