C-13 NUCLEAR MAGNETIC-RESONANCE OF ETHYLENE-PROPYLENE COPOLYMER AND DETERMINATION OF SEQUENCE DISTRIBUTION OF MONOMERIC UNITS

The **1**3NMR spectra of ethylene-propylene copolymers and their model compounds were measured at 15. 1 MHz. Assignments of the signals were carried out by using the equation of Grant and Paul and also by comparing the spectra with those of squalane, hydrogenated natural rubber, PE, and atactic PP. On the basis of these results the mole fractions of the four types of the dyad sequences, that is, the propylene-propylene (head-to-tail and head-to-head), the ethylene-propylene, and the ethylene-ethylene sequences, were determined together with the average sequence lengths of both monomer units.