Compositional and Configurational Assignments of Acrylonitrile Copolymers by 2D NMR Spectroscopy

摘要

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 ~(13)C- and ~1H-NMR spectra were done with the help of Distortionless Enhancement by Polarisation transfer (DEPT) and two dimensional ~(13)C-~1H Heteronuclear Single Quantum Correlation (HSQC) and Total Correlated spectroscopy (TOCSY) experiments. The methylene, methine and methyl (A/M and A/G) carbon resonances show 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 ~1H NMR spectrum to different compositional sequences.