Sequence determination of vinyl acetate–methyl acrylate copolymers by NMR spectroscopy

Vinyl acetate/methyl acrylate (V/M) copolymers were prepared by free-radical solution polymerization in benzene. Copolymer compositions were obtained from ¹H-NMR spectroscopy. Reactivity ratios for the copolymerization of V with M were calculated using the Kelen-Tudos (KT) and the nonlinear error in variables (EVM) methods. The reactivity ratios obtained from the KT and EV methods are r_V = 0.04 ± 0.03 and r_M = 7.28 ± 2.88 and r_v = 0.04 ± 0.01 and r_M = 7.28 ± 0.37, respectively. The microstructure was obtained in terms of the distribution of V- and M-centered triad sequences from ¹³C{¹H}-NMR spectra of copolymers. Homonuclear ¹H-2D-COSY and 2D-NOESY NMR were used to determine the most probable conformer for the V/M copolymer. The copolymerization behavior of the V/M copolymers as a function of conversion is also reported. © 1994 John Wiley & Sons, Inc.