Polymerization of monomers containing chlorine by the action of organic transition metal compounds

Abstract

A study was made of polymerization of chloroprene, 2,3-dichlorobutadiene and vinylchloride by the action of organometallic compounds of titanium, nickel, chromium and vanadium with a σ- or π-allyl bond of metal-carbon. Polymerization of chloroprene and vinylchloride was carried out in aromatic, aliphatic and chlorinated hydrocarbons. It was established that polymerization of chloroprene takes place at the highest rate in aromatic hydrocarbons, process rate increasing on transition from benzen to toluence and even to o-xylene. It was found that polymerization of vinyl chloride by the action of tetrabenzyl titanium takes place in methylene chloride forming an amorphous polymer. It was found that independent of the type of organometallic initiator, the polychloroprene formed has a 1,4- trans-structure. A study of the consumption of benzyl groups at the titanium atom during polymerization of chloroprene by the action of tetrabenzyl titanium shows that in contrast to polymerization of butadiene, all titanium-benzyl bonds of the initial organic titanium compound take part in initiation. It was established that the activity of π-alkenyl nickel halides during polymerization of chloroprene is independent of the type of halide in the organic nickel compound. Relative activities of monomers containing chlorine during polymerization with dienes and olefins confirm the coordination mechanism of polymerization.