N-vinyl-2-pyrrolidone and methacrylonitrile copolymers: nuclear magnetic resonance characterization

The copolymers of N-vinyl-2-pyrrolidone and mediacrylonitrile (V/N) were prepared by free radical bulk polymerisation. The copolymer composition was determined from the quantitative C-13{H-1} NMR spectrum. The reactivity ratios for N-vinyl-2pyrrolidone (V) and methacrylonitrile (N) were found to be r(V) = 0.04, r(N) = 1.56. The complete spectral assignment of the overlapped and complex carbon and proton NMR spectra were done with the help of two dimensional C-13-H-1 Heteronuclear Single Quantum Correlation Spectroscopy (HSQC) and Total Correlation Spectroscopy (TOCSY). Distortionless Enhancement by Polarization Transfer (DEPT) was used to differentiate between the methylene, the methine and the methyl carbon resonance signals of the copolymers. (C) 2003 Elsevier Science B.V. All rights reserved.