ADDITIVITY OF C-13 NMR CHEMICAL-SHIFTS AND CLASSIFICATION OF STRUCTURAL FRAGMENTS FOR THE ETHYLENE-PROPYLENE COPOLYMER CHAIN

A classification of the structural fragments in the ethylene-propylene copolymer chain and the corresponding signals in the C-13 NMR spectru m of this copolymer is proposed. Within the framework of this classifi cation, the positions of signals due to methylene and methine carbon a toms observed in the NMR spectra of the copolymer agree with the spect ra calculated by the proposed additive scheme. The values of additive increments of the chemical shifts of resonant carbon atoms in various structural fragments were determined from the results of high- resolut ion C-13 NMR measurements including experiments in the DEFT mode.