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

Abstract

AbstractVinyl 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 rV = 0.04 ± 0.03 and rM = 7.28 ± 2.88 and rv = 0.04 ± 0.01 and rM = 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.