Boron-moiety-containing aluminoxanes (BMAOs) were prepared from the partial protonolysis of Me3Al using various arylboronic acids. Compared with methylaluminoxane (MAO) generated from the hydrolysis of Me3Al, BMAO prepared from C6F5B(OH)2 and Me3Al induced a higher activity at the same Al/Ti ratio in the Ti-based olefin polymerization catalyst (ansa-Me2Si(Flu)(NBu) TiMe2; 5). The time course of...

The (salen)Co(III) complex 1 tethering four quaternary ammonium salts, which is a highly active catalyst in CO2/epoxide copolymerizations, shows high activity for propylene oxide/phthalic anhydride (PO/PA) copolymerizations and PO/CO2/PA terpolymerizations. In the PO/PA copolymerizations, full conversion of PA was achieved within 5 h, and strictly alternating copolymers of poly(1,2-propylene ph...

The synthesis of a series of C1-symmetric metallocene complexes rac-[1-(5,6-dialkoxy-2-methyl1-η5-indenyl)-2-(9-η5-fluorenyl)ethane]zirconium dichlorides (alkyl: n-butyl, n-hexyl, n-octyl, ndecyl) is described. These complexes are versatile catalysts in the polymerization of propylene after in situ activation with triisobutylaluminum (TIBA) and Ph3C[B(C6F5)4] in toluene and heptane solution. Al...

Poly(propylene adipate)-block-poly(ɛ-caprolactone) copolymers were synthesized using a combination of polycondensation and ring-opening polymerization of ɛ-caprolactone in the presence of poly(propylene adipate). Gel permeation chromatography was used for molecular weight determination, whereas hydrogen-1 nuclear magnetic resonance and carbon-13 nuclear magnetic resonance spectroscopy were empl...

Phosphates represent diverse complex systems, whose basic structural unit is tetrahedron. They are widely applied as catalysts, carriers of catalytic active substances, adsorbents and ion exchangers. Phosphoric acid phosphates act catalyst for reactions alkylation, cracking, izomerization, polymerization, hydrogenation dehydrogenation. some metals promote oxidation normal alkanes with derivatio...

The stereospecific polymerization of conjugated dienes began in 1954 with the first catalysts obtained by combining TiCl4 or TiCl3 with aluminum-alkyls, i.e. the catalytic systems previously employed for ethylene and propylene polymerizations. Subsequently, many other catalytic systems were obtained and examined by a combination of transition metal or lanthanide compounds with appropriate alkyl...