The new highly active supported vanadium-magnesium catalyst (VMC) has been studied in α-olefin (1-butene, 1-hexene)/ ethylene copolymerization in the presence of hydrogen. Data on the effect of α-olefin/ethylene ratio in copolymerization on the content of branchings in copolymers, kinetic profile, copolymer yield, molecular weight and molecular weight distribution of copolymers have been obtain...

Heteroatom-functionalized polyolefins are of fundamental interest and practical importance. This has spurred investigations of the copolymerization of polar and nonpolar olefins. We report the first syndiospecific polymerization of a series of heteroatom-containing α-olefins and their copolymerization with ethylene catalyzed by half-sandwich rare-earth complexes. We have found that the interact...

A series of bimetallic organo-group 4 "constrained geometry" catalysts and binuclear bisborane and bisborate cocatalysts have been synthesized to probe catalyst center-catalyst center cooperativity effects on olefin enchainment in homogenous olefin polymerization and copolymerization processes. Significant nuclearity effects are found versus mononuclear controls, and the effect can be correlate...

beside ziegler-natta and phillips catalysts the development of methylaluminoxane (mao) as cocatalyst incombination with metallocenes or other transition metal complexes for the polymerization of olefins haswidely increased the possibilities in controlling the polymer composition, polymer structure, tacticity and special properties with high precision. these catalysts allow the synthesis of isot...

Long-chain branches and narrow molecular weight distribution is a novel structure combination in polyethene, which has only been possible to achieve with single-center catalysis. Long-chain branches, even at very low concentrations, have a strong effect on the polymer melt behavior and, thereby, the processing properties. This work deals with ethene polymerization using group IV metallocene cat...

heterogeneous ziegler-natta and homogeneous metallocene catalysts exhibit greatly different active sitenature in olefin polymerization. in our previous study, it was reported that mgcl2-supported titanocenecatalysts can generate both ziegler-natta-type and metallocene-type active sites according to the type of activators.the dual active site nature of the supported titanocene catalysts was furt...

Heterogeneous Ziegler-Natta and homogeneous metallocene catalysts exhibit greatly different active sitenature in olefin polymerization. In our previous study, it was reported that MgCl2-supported titanocenecatalysts can generate both Ziegler-Natta-type and metallocene-type active sites according to the type of activators.The dual active site nature of the supported titanocene catalysts was furt...

An amine bis(phenolate) dibenzyl titanium complex having a methoxy donor on a side arm leads, upon activation with tris(pentafluorophenyl)borane, to unique living properties in alpha-olefin polymerization: exceptionally high molecular weight poly(1-hexene) is obtained in a living fashion at room temperature, living polymerization of 1-hexene is obtained above room temperature, and block copolym...

Copolymerization of racemic alpha-olefins with ethylene and propylene was carried out in the presence of enantiopure C1-symmetric ansa metallocene, {1,2-(SiMe2)2(eta5-C5H-3,5-(CHMe2)2)(eta5-C5H3)}ZrCl2 to probe the effect of the polymer chain end on enantioselection for the R- or S-alpha-olefin during the kinetic resolution by polymerization catalysis. Copolymerizations with ethylene revealed t...

Copolymerization of racemic -olefins with ethylene and propylene was carried out in the presence of enantiopure C1-symmetric ansa metallocene, {1,2-(SiMe2)2( -C5H-3,5-(CHMe2)2)( -C5H3)}ZrCl2 to probe the effect of the polymer chain end on enantioselection for the Ror S-olefin during the kinetic resolution by polymerization catalysis. Copolymerizations with ethylene revealed that the polymer cha...