Nuclear magnetic resonance studies on microstructure of ethylene copolymers. VI. Carbon‐13 spectra of ethylene–vinyl acetate copolymers

Abstract

The 22.6‐MHz Fourier‐transform noise‐decoupled ¹³C (carbon‐13) NMR spectra of several ethylene–vinyl acetate (E–VA) copolymers were obtained. We found that triad information on monomer placement can be deduced from carbonyl resonances, triad and pentad information can be deduced from methine carbon resonances, and triad information is available from the methylene carbon resonances. The random comonomer distributions in E–VA polymerizations were demonstrated up to pentad placements. In addition, the use of model‐compound data in the analysis of copolymer spectra was shown.