C-13-NMR STUDY OF ETHYLENE 1-HEXENE AND ETHYLENE/1-OCTENE COPOLYMERS OBTAINED USING HOMOGENEOUS CATALYSTS/

This study employed the C-13-NMR spectroscopy to investigate the influ ence of the increase of the comonomer concentration on the microstrutu re of ethylene/1-hexene and ethylene/1-octene copolymers obtained by t he use of MeSiCp(2)ZrCl(2), Cp(2)ZrCl(2),, Et[Ind]2ZrCl2 and [Ind]2ZrC l2 catalysts. For both comonomers butyl or hexyl branches were isolate d between ethylene blocks. As the alpha-olefin concentration in the co polymer increased, butyl or hexyl branches became closer, some of them , separated by only one or two ethylene units. Incorporation of alpha- olefin in the copolymer was higher for the bridged catalysts, MeSiCp(2 )ZrCl(2), and Et[Ind]2ZrCl2 than for the unbridged ones. The alpha-ole fin size did not seem to effect its reactivity towards ethylene.