Tacticity, sequence distribution, anomalous linkages, and alkyl chain branching in ethylene-vinyl alcohol copolymers as studied by proton and carbon-13 NMR

Abstract

A careful reexamination of the 200-300-MHz 1H NMR spectra of ethylenevinyl alcohol (E-VOH) copolymers has led to a complete assignment (on a triad level) of all observed methine and hydroxyl resonances. Compositional sequence data and configurational sequence placements (tacticity) have been obtained from 1H and 13C NMR spectra. The limitations of 1H and 13C NMR methods for the determination of anomalous structures and nonhydrolyzable chain branching are discussed.