Compositional and stereochemical analysis of acrylamide vinyl acetate copolymers by one- and two-dimensional NMR spectroscopy

Acrylamide/vinyl acetate copolymers were prepared by solution polymerizatio n using benzoyl peroxide as the initiator. The copolymer composition was de termined from the percent nitrogen in the copolymers. The comonomer reactiv ity ratios determined using Kelen-Tudos and nonlinear error-invariable meth ods are r(A) = 9.28 +/- 0.6 and r(V) = 0.09 +/- 0.006. The triad sequence d istributions in terms of A- and V-centered triads have been obtained from C -13{H-1} NMR spectra of the copolymers. The methine and the methylene carbo n signals were assigned to compositional (triad, tetrads, and pentads) and configurational (triads) sequences. The broad and overlapping H-1 NMR spect ra were assigned with the help of 2D inverse-HETCOR and TOCSY experiments.