Journal of Applied Polymer Science, Vol.99, No.5, 2174-2181, 2006
Microstructure analysis of methyl acrylate/methyl methacrylate copolymers by two-dimensional NMR spectroscopy. II
In the present article, a comprehensive two-dimensional heteronuclear multi bond correlation (HMBC) spectral analysis of methyl acrylate (A)/methyl methacrylate (B) copolymers is reported. The methylene carbon and methine carbon resonances assigned from the 2D HSQC spectroscopy were established by analyzing the two and three bond order couplings with alpha-methyl protons, methylene protons, and methine protons. Quaternary carbon resonances of the B unit were assigned by investigating the two bond order couplings with a-methyl protons and methylene protons. Assignments of carbonyl carbon resonances based on the analysis of three bond couplings with a-methyl protons and methylene protons are reported. The analyses present comprehensive assignments of the carbonyl carbon resonances showing the critical contribution of 2D HMBC spectroscopy in the indirect analysis of carbon resonances.