GR76205

A novel process is disclosed for polymerizing and copolymerizing alpha olefins (ethylene included) also in the presence of conjugated diolephins, and more particularly for copolymerizing ethylene with 1,3-butadiene, based on the use of a plural-component catalyst system, one of said components being a novel complex which contains titanium and magnesium. The process gives, in yields higher than 200,000 grams of polymer per g of elemental Ti, ethylene-butadiene copolymers having a distribution of monomeric units characterized by a particular novel 13C-NMR spectrum, a high apparent specific gravity and such a grit size as to impart flowability to the dry product, and a distribution in the presence of sulphur and accelerators such as to acquire a gel content (fraction insoluble in boiling xylenes) over 50%.