Silica powder obtained by sol-gel method as a support of organometallic vanadium catalyst for ethylene polymerization

Abstract

lUM-7l oG' H ' ', łm.'ccz,Ą],Ą '\AT^lI^\U'KoVĄlF\A Silica powder obtained bysol-8el metho.l as a support of ortanometalli. vanadium catalyst for ethylene polymerization RAPID COMMUNICATION sumnary Sol gcltc.hniquc was enployed roobbin thc s ili.i,iy p. pow d.i vhich aftcl nrodjfi.iiion proredure was aPPlicd a suppoł 01Ór ganondi]li. c ilyiic syśen for rdlylĆne polyń iz iol Tlt powds PrG dud lvis synlhcsju.d usins hydblysis ańd condcnsation 01TEos, rhl],zcd by mmoi.' obbin€ d młłial and a Ęfer.Dc suPpolt (.omnelciil 'lrc Davisil) lvere d'aradd]zed lo deiemmc thef Palticl€ si? dishńutjons, BET surla.e al.a, porc voluńc and diamcie. Gis.phase adsorption of Vanadju cłblyśoń'nalyzcdsuPPo m eliłhaswPllasadsorPiionhonthesolution atrił mabria ls wcrc ihem a lly pret.a lod Pnor.ih]vti. sy9ems syntlrcas and thĆ innucn.c ol modjfi.atnrn ńethod apPlild on rr llins ol8anońctallic c alyś.hiracfu wa5 $titahd in low-Pr*slte slufy Polvńdizahon ot cihylcn.' obhimd l$ul6 Prov. dttsol. gel ńabńal' duc to its advinbgeous moĘhologv Wth widc łnd shal]o\' Pl[cs, allows b obhin cahlytic sydons o1lĘher adiYity in low_preŚue ethy lcn. polymcńz.iion, in conPa dsol wi lh Ćońn {cń l sili.a Davis il '

Chlorotitanium (IV) tetradentate Schiff‐base complex immobilized on inorganic supports: Support type and other factors having effect on ethylene polymerization activity

“…That decrease of the titanium loading may be attributed to the presence of methyl group. It was observed earlier for the VOCl 3 catalyst immobilized on silica type sol‐gel carriers that the vanadium content in the catalyst dropped down after the carriers were used which contain methyl groups 12(c). The reduced share of the complex in the course of synthesis results in lower amounts of immobilized titanium (Table 2), irrespective of the type of the carrier used.…”

“…The difference in the latter results predominantly from the types of precursors which were used in their synthesis; TEOS was used for the synthesis of SG and powders SG 0.2Me and SG 0.8Me were obtained by the replacement of 20 or 80%, respectively, of TEOS with methyltriethoxysilicate (Table 1). The use of a precursor with a nonhydrolyzing SiC bond allows for the chemical modification of the surface which gives materials having methyl groups in addition to hydroxyl groups 12(b)…”

“…Thermal treatment of silica, as it was told earlier, removes water and generates totally hydroxylated silica (110 °C), and the number of silanol groups is dependent on the drying temperature, varying from 5.0 OH nm −2 (110 °C) to 1.5 OH nm −2 (450 °C) 5(c). All silica materials which were used in this work were calcined at 200 °C because that temperature was found to be optimum for that type of silica carriers 12(b). As can be seen in Table 2, the used silica grades had different surface properties.…”

“…Suspension of silica (Davisil) n ‐hexane was subjected to grinding over 21 h in a ball grinder to reduce the grain size for that material 12(a). The procedure presented in12 was followed to synthesize the silica materials with the use of the sol‐gel technique. Tetraethoxysilane or tetraethoxysilane and methyltriethoxy‐silicate were used as precursor.…”

(Co)polymerisation Behaviour of Supported Metallocene Catalysts: Carrier Effect

“…It was selected because our earlier ethylene homopolymerisation studies revealed that such materials improved the activity of the catalytic system. [28] The silica-type sol-gel product, with no previous modification by the organoaluminium compound, was used directly in the synthesis of heterogeneous metallocene catalysts. The amount of zirconium anchored to its surface turned out to be nearly the same as that deposited on MgCl 2 (MeOH) 6 and higher than the amount of zirconium anchored to the magnesium chloride and tetrahydrofuran complex (Table 1).…”