Olefin polymerization catalysis is a domain of major research activity. For the last decade, much of this research has been focused in the area of metallocene catalysis, which has been at the front line in driving important technology renewal in the polyolefins industry. Developments in metallocene catalysis have instigated much trade press discussion, and now emerging nonmetallocene catalyst s...

One of the most efficient and versatile ways to synthesize polyolefin nanocomposites is the in-situ polymerization of olefins in the presence of nano particles by metallocene catalysts. Metallocene/methylaluminoxane (MAO) catalysts are soluble in hydrocarbons and therefore they can be absorbed perfectly in solution onto the surface of particles or fibers and after addition of ethene or propene ...

1-Pentene, respectively 1-hexene, were reacted with 13 homogeneous metallocene catalysts to give linear oligomerization products, predominantly dimers, with selectivities above 90%. The product distributions of the codimerization reactions of 1-pentene with 1-hexene reflected a binomial behaviour. Therefore, the ratio for dimers is 1:2:1 (C10:C11:C12) while the trimers (pentadecenes up to octad...

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...

Several types of hybrid catalysts are made through mixing of 4th generation Ziegler-Natta (ZN) and (2-PhInd)2ZrCl2  metallocene catalysts using triethylaluminum (TEA) as coupling agent. Response surface methodology (RSM) is used to evaluate the interactive effects of different parameters including amounts of metallocene and TEA and temperature on metallocene loading. Analyzing the amounts of Al...

several types of hybrid catalysts are made through mixing of 4th generation ziegler-natta (zn) and (2-phind)2zrcl2metallocene catalysts using triethylaluminum (tea) as coupling agent. response surface methodology (rsm)is used to evaluate the interactive effects of different parameters including amounts of metallocene and tea andtemperature on metallocene loading. analyzing the amounts of al and...

highly active metallocenes and other single site catalysts have opened up the possibility of polymerizing cycloolefins such as norbornene (n) or of copolymerizing them with ethene (e) or propene (p). the polymers obtained show exciting structures and properties. e-n copolymers are industrially produced materials, with variable and high glass transitions depending on the wide range of their micr...

Understanding the kinetics of olefin polymerization with Ziegler-Natta and related catalysts means identifying the main kinetic parameters such as k(p) and concentration of active sites. The high-pressure quenched-flow technique could be an absolute method for counting active sites and for activation studies of molecular catalysts. A kinetic study of metallocene catalysts and a phenoxy-imine ti...

a variety of group 4 metal catalytic systems (c2-symmetric {ebthi}-, {sbi}-type zirconocene complexes (c2-1–4); c1-symmetric (c1-5–8) and cs-symmetric (cs-9) {cp/flu}-type zirconocene complexes; cp*2zrcl2 (cp* 2-10)), half-metallocene complexes (cpticl3, hm-11), constrained-geometry (cgc-12) titanium catalysts) and post-metallocene catalysts (dow’s ortho-metallated amido-pyridino hafnium comple...