Melamine triazine ring spectra

The NMR spectrum of the M-DME resin with molar ratio M DME =1 2 shown in Fig. 3 is very similar to that of the U-DME. Major difference is represented by the C=N groups of the triazine ring of the reacted melamine that did not appear in the U-DME spectrum (Table 3). As melamine presents three reactive amine groups and due to the resin molar ratio (M DME = 1 2), a large majority of the DME seemed to have reacted. However, no trace of DME reacted with two... 

The Raman spectrum of the melamine resin has a weak band at 3400 cm assigned to both NH and OH groups (note in the Raman spectrum that the NH will often be more intense). Bands at 819 cm and at 977 and 675 cm are attributed to the melamine moiety [83]. The amide-I and triazine ring bands are observed at 1630 and 1560 cm, respectively. 

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