Methyl acrylate - N-vinyl carbazole

1 aromatic hydrocarbons and aromatic proton 8a aromatic hydrocarbons 

Visual inspection of the aromatic region of the spectra of pNVC and copolymers 1 and 5, reveals that the eight aromatic protons resonate in three groups and that relative intensities change as the concentration of NVC increases. In addition, a new peak appears at 5.0 ppm when the concentration of NVC is above 44%. This signal, which corresponds to one proton in pNVC, is assigned to shielded proton 1. Integration alone is not sufhcient, yet when combined with hetero- and homo-nuclear shift correlation, it becomes possible to identify the components of these peaks. 

The good agreement between experimental and predicted sequence distributions suggests that the terminal model applies to the copolymerisation of MA with NVC when NVC contents are relatively low. Lack of correlation between calculated and experimental compositions arising from feeds with high NVC concentrations is not relevant to further investigations since the copolymers studied contain less than 40% NVC. 

Three of the resonances are particularly suited to assessment of the isolation of NVC in a copolymer carbon 1 and shielded proton 1 of NVC and the carbonyl carbon of 

Though sequence distributions calculated from reactivity ratios can effectively describe the distribution and isolation of NVC units in copolymers with low NVC concentrations, analysis of carbon spectra for the three resonances described above provides a more convenient evaluation. 

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