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

摘要

Acrylamide/vinyl acetate copolymers were prepared by solution polymerization using benzoyl peroxide as the initiator. The copolymer composition was determined from the percent nitrogen in the copolymers. The comonomer reactivity ratios determined using Kelen-Tudos and nonlinear error-invariable methods are r(A) = 9.28 +/- 0.6 and r(V) = 0.09 +/- 0.006. The triad sequence distributions 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 carbon signals were assigned to compositional (triad, tetrads, and pentads) and configurational (triads) sequences. The broad and overlapping H-1 NMR spectra were assigned with the help of 2D inverse-HETCOR and TOCSY experiments. [References: 14]