Sequence distribution in ethylene-propylene copolymers. II. The 13C NMR spectra,multad populations,and kinetic parameters

Monad, dyad, and triad populations have been derived from the ¹³C NMR spectra of eight ethylene-propylene copolymers. Using these values, Kinetic parameters of the polymerization have been calculated, including conditional probabilities, and reactivity ratios. The fraction of propylene entering in an inverted order has been found to be about 20%. The copolymerization is dominated by the relatively large reactivity of ethylene. There is an alternating tendency for the two monomers which is evident both in the normal addition of propylene and the inverted addition. Penultimate effects do not play a significant role.