Compositional and configurational assignments of acrylonitrile copolymers by 2D NMR spectroscopy

The copolymers of acrylonitrile with methyl methacrylate (A/M), Glycidyl methacrylate (A/G) and acrylic acid (A/B) of different monomer concentrations were prepared. The carbon-13 and proton spectra of these copolymers are overlapping and complex. The complete spectral assignment of C-13- and H-1-NMR spectra were done with the help of Distortionless Enhacement by Polarisation transfer (DEPT) and two dimensional C-13-H-1 Heteronuclear Single Quantumn Correlation (HSQC) and Total Correlated spectroscopy (TOCSY) experiments. The methylene, methine and methyl (A/M and A/G) carbon resonances chow both stereochemical (triad level) and compositional (dyad, triad, tetrad, pentad and hexad level) sensitivity. 2D Double Quantum Filtered Correlated Spectroscopy (DQFCOSY) experiment was used in A/B copolymers to assign the complex H-1 NMR spectrum to different compositional sequences.