Copolymerizantion of Propylene with Butadiene or Ethylene by Ziegler Type Catalysts

Abstract

Copolymerization of propylene-butadiene by AlEt₃-TiCl₄ catalyst and copolymerization of ethylene-propylene by AlEt₃-VCI₄ catalyst were carried out. In both cases copolymers obtained by the catalysts prepared in the presence of only propylene gave more propylene content than that obtained by the catalyst prepared in the presence of both monomers. In ethylenepropylene copolymerization both kinds of catalysts, prepared in the presence of only ethylene and monomer mixtures gave copolymers having the same composition. From the IR spectra measurement and the fractional precipitation of ethylene-propylene copolymer, it was found that the copolymer molecules contained comparatively long sequences of methylene unit.
From these results, it was concluded that the copolymerization activity of the catalysts varried with the kind of the olefin present during the catalyst forming, and the difference of the activity was assumed to be due to the substantial change of the catalyst or variation of the surface structure of the catalyst species which affects to the absorption of monomers on the catalysts. In ethylene-propylene copolymerization a tendency to produce a block copolymer was found.