Effects of hydrogen and external donor on performance of butene-1 polymerization catalyzed by supported Ziegler-Natta catalyst

The effects of hydrogen and alkoxysilanes as external donors on the polymerization of bu-tene-1 with supported Ziegler-Natta catalysts were studied, and the polymers were characterized by GPC, DSC and the polarized light microscope analysis. The results showed that the polymerization activity first increased and then decreased with the increase of the amounts of hydrogen. The highest catalytic activity and the best product isotacticity could be obtained when DCPMS was used as the external donor. Molecular mass of polybutene-1 increased with reducing the dose of hydrogen and increasing external electron donor alkyl-space volumes. The molecular weight apparently affected the crystallization of the polymers, with M w=23.5 × 10 4 g/mol, the polybutene-1 showed the highest melting point and crystallinity.