One‐ and two‐dimensional NMR characterization of N ‐vinyl‐2‐pyrrolidone/methyl acrylate copolymers

N ‐vinyl‐2‐pyrrolidone/methyl acrylate (V/M) copolymers were prepared by free‐radical bulk polymerization using benzoyl peroxide as an initiator. The copolymer composition of these copolymers was calculated from 1 H NMR spectra. The radical reactivity ratios for N ‐vinyl‐2‐pyrrolidone (V) and methyl acrylate (M) were r V = 0.09, r M = 0.44. These reactivity ratios for the copolymerization of V and M were determined using the Kelen–Tudos and nonlinear least‐squares error‐in‐variable methods. The 13 C{ 1 H} and 1 H NMR spectra of these copolymers overlapped and were complex. The complete spectral assignment of the 13 C and 1 H NMR spectra were done with distortionless enhancement by polarization transfer and two dimensional 13 C‐ 1 H heteronuclear single quantum correlation spectroscopic experiments. The two‐dimensional 1 H‐ 1 H homonuclear total correlation spectroscopic NMR spectrum showed the various bond interactions, thus inferring the possible structure of the copolymers. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2225–2236, 2002