Borate and MAO Free Activating Supports for Metallocene Complexes

Abstract

Fluorinated activating supports (AS) for metallocene complexes were prepared via treatment of silica with AlEt3 or AlEt2F followed by pyrolysis and combustion steps, and a subsequent fluorination step when AlEt3 was used. This new family of activators appears to be universal for metallocene complexes leading to catalysts displaying high activities in ethylene polymerization without the addition of MAO. A productivity of 3200 g gAS –1 was obtained in 1 h with the catalyst rac-Et(Ind)2ZrCl2/AS8/Al(iBu)3 at 80 °C under 10 bar of ethylene. An isotactic polypropylene with a melting transition at 145 °C was prepared using rac-Me2Si(2-Me-benz(e)Ind)2ZrCl2 activated by AS9 and Al(iBu)3. The spherical particle morphology of polyolefins was particularly adapted to slurry processes employed in industry.

Activation and Deactivation of the Polymerization of Ethylene over rac‐EtInd2ZrCl2 and (nBuCp)2ZrCl2 on an Activating Silica Support

“…The catalysts supported on the activated silica supports were synthesized as described by Prades et al The physical properties of silica before treatment, as well as the properties of the activating support (M3703/079A) made using the Sylopol 952 silica are given in Table . The metallocene complex was pre‐contacted with the support for 10 min before introduction in the reactor.…”

“…The research group of Boisson developed an interesting alternative to the use of MAO using a new preparation method for heterogeneous metallocene catalysts . They developed activating silica support based on aluminum and fluor, in which the fluoro‐ligand is directly linked to the aluminum.…”

“…The principle objective of the current study is to obtain a better understanding of what influences the kinetics of ethylene polymerization using rac ‐EtInd 2 ZrCl 2 as the precursor on the fluorinated support used in our previous studies . Another objective of this work is to gain insight on the impact of the support on the properties of a chiral ansa metallocene.…”

Bridging the Gap between Industrial and Well‐Defined Supported Catalysts

“…[397][398][399] Ther eaction of supported MAOw ith am olecular complex generates active materials for polymerization that behave similarly to metallocene complexes activated by MAOi ns olution. [402] These supports are comparable with supported MAOs ystems in terms of the activity [401] Activating supports based on silica-supported fluorinated aluminum species were prepared by either reacting AlEt 3 with silica before as ubsequent fluorination with NH 4 SiF 6 or directly by reacting AlEt 2 Fw ith silica.…”

“…[402] These materials are interesting supports and require more rigorous characterization of the surface sites. [402] These materials are interesting supports and require more rigorous characterization of the surface sites.…”