Ethene/propene/diene copolymerizations

Processes of ethene/a-olefin copolymerization are of great practical importance. Copolymerization of ethene with small amounts of highest a-olefins (1-butene, 1 -hexene, 1 -octene) allows one to produce linear low density polyethylene (LLDPE), which is one of the most widely used large-scale polyolefin products. Polypropylene, modified with small amounts of ethene, exhibits higher impact strength compared to isotactic homopolypropylene. Copolymerization of propene with large amounts of ethene and terpolymerization of ethene/propene/diene result in amorphous elastomer materials (rubbers) [103]. 

Mw/M = 2, highly linear Copolymerization random distribution, LLDPE co-monomers propene, 1-butene, 1-octene Elastomers, Terpolymers of Ethene, Propene and Diene low transition metal concentration in the polymer, narrow molecular weight distribution Polymerization to ... 

Galimberti, M. Piemontesi, F. Fusco, O. Metallocenes as Catalysts for the Copolymerization of Ethene with Propene and Dienes. In Metallocene-based Polyolefins Preparation, Properties and Technology, Scheirs, J., Kaminsky, W., Eds. Wiley Chichester, 2000 Vol. 1, p. 309. 

The copolymerization of ethene with a variety of other alkenes or dienes was also studied. The copolymerization of supercritical mixtures of ethene and propene (120-220 °C and 1000-1500 bar) was catalyzed by the silyl-bridged bis-(tetrahydroindenyl)zirconocene catalyst 19 and MAO at a metallocene concentration of 6 X 10 mole fraction and an Al Zr ratio of 22000 [92]. With a 50 50 mixture of SCC2H4 and scCsHg, the resulting polymer had only 8% incorporation of propene. Increasing concentrations of propene resulted in... 

One of the features of olefin copolymerization kinetics is the effect of comonomer on the rate of ethene or propene polymerization during ethene/a-olefin or propene/ a-olefin copolymerization, i.e., the so-called comonomer effect (CEF). The rate enhancement of ethene or propene polymerization in the presence of a comonomer is observed for conventional ZN catalysts [80, 113-123] and for homogeneous [124-133] and supported metallocenes [134—136] and post-metallocenes catalysts [137-140]. The increase in activity was remarked in the presence of such comonomers as propene, 2-methylpropene, 1-butene, 3-methylbutene,4-methylpentene-l, 1-hexene, l-octene,l-decene, cyclopentene, styrene, and dienes. 

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