CARBON-13 NUCLEAR MAGNETIC RESONANCE ANALYSIS OF ETHYLENE OXIDE-MALEIC ANHYDRIDE COPOLYMERS

Natural abundance 13C white noise decoupled nmr spectra of poly (ethylene oxide) and some ethylene oxide-maleic anhydride copolymers have been obtained at 25.1 MHz. The copolymer spectra are interpreted in terms of triads and pentads of monomers in the chain providing both short- and long-range information about chain structure. The relative chemical shifts of the carbons in the central units of these sequences are opposite to and more than an order of magnitude larger than those of the protons in the same units. The 13C shifts correlate with differences in the local π-electron density, while the 1H shifts correlate with neighbor anisotropic shielding effects of adjacent functional groups. © 1969, American Chemical Society. All rights reserved.