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~(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 model compounds, then used in measurements of number average molecular weights. The higher limit of an exact determination of the end group signal is less than a molecular weight of 10 ~ 4. For polymer samples with M_n <10 ~ 3, the results obtained from ~ (13) C-NMR spectra of saturated carbon regions are in excellent agreement with the values determined by ~ 1H-NMR, SEC, and VPO methods, while the results from ~ (13) C-NMR spectra ofphenyl C-1 carbon regions are somewhat higher than the values determined by other methods.