Combined polymerization catalysis of nickel complex and zirconocene for branched polyethylene
نویسندگان
چکیده
منابع مشابه
Cationic alkylaluminum-complexed zirconocene hydrides as participants in olefin polymerization catalysis.
The alkylaluminum-complexed zirconocene trihydride cation [(SBI)Zr(μ-H)(3)(Al(i)Bu(2))(2)](+), which is obtained by reaction of (SBI)ZrCl(2) with [Ph(3)C][B(C(6)F(5))(4)] and excess HAl(i)Bu(2) in toluene solution, catalyzes the formation of isotactic polypropene when exposed to propene at -30 °C. This cation remains the sole observable species in catalyst systems free of AlMe compounds. In the...
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Reduction of Zr(IV) metallocenium cations with sodium amalgam (NaHg) produces EPR signals assignable to Zr(III) metallocene complexes. The chloro-bridged heterodinuclear ansa-zirconocenium cation [(SBI)Zr(μ-Cl)2AlMe2](+) (SBI = rac-dimethylsilylbis(1-indenyl)), present in toluene solution as its B(C6F5)4(-) salt, thus gives rise to an EPR signal assignable to the complex (SBI)Zr(III)(μ-Cl)2AlMe...
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The effect of short-chain branching (SCB) on the persistence length lp of polyethylene (PE) was studied using small-angle neutron scattering (SANS). In thermodynamically good solvents, lp can be measured directly from the scattering vector qtr at the crossover from good solvent mass-fractal scaling to the rodlike persistent scaling, using the unified equation described in the text. The method w...
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In this study, we developed a metal-free biosynthetic strategy of enzymatic polymerization to fabricate aliphatic poly(pentamethylene carbonate) (PPMC). Novozym-435 lipase showed considerably high catalytic efficiency, and high molecular weights (Mn) of up to 6.0 104 g mol 1 were readily achieved through the ring-opening polymerization of cyclobis(pentamethylene carbonate). The reaction paramet...
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Two-arm branched mPEG (monomethoxy-polyethylene glycol) with different molecular weights (M(n)=4000, 6000, 9400) was synthesized and used as carrier for immobilization of cisplatin [cis-diammine(dichloro)platinum (II), CDDP]. As a contrast, CDDP modified with linear mPEGs was also synthesized. All these polymeric drugs modified with branched mPEG are water soluble and show higher cytotoxic acti...
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ژورنال
عنوان ژورنال: Open Chemistry
سال: 2003
ISSN: 2391-5420
DOI: 10.2478/bf02475220