A Novel (SiO₂/MgO/MgCl₂)·TiCl_x Ziegler–Natta Catalyst for Ethylene and Ethylene/1‐Hexene Polymerization

Abstract

A novel (SiO 2 /MgO/MgCl 2 )·TiCl x Ziegler-Natta catalyst for ethylene and ethylene/1-hexene polymerization is successfully developed through impregnation of aqueous solution of watersoluble Mg-compounds such as magnesium acetate on silica gel, and forming a supported thin layer of magnesium oxide on the surface of SiO 2 after high temperature calcination in dry air or oxygen, followed by further reacting with titanium tetrachloride to synthesize the magnesium dichloride carrier in situ and to support the titanium species simultaneously. The method is relatively simple and the resulting catalysts exhibit high activity, good hydrogen response, and copolymerization ability with high 1-hexene incorporation. Unlike the traditional industrial Ti/Mg Ziegler-Natta catalysts using the relatively expensive, anhydrous and moisture-sensitive MgCl 2 , Mg(OEt) 2 , MgR 2 or RMgCl as Mg-sources, the most unique feature of this novel catalyst is its capability of utilization of any soluble Mg-compounds and thus shows great potential for application in commercial gas-phase polyolefi n processes.

Vanadium Modification Effects on the (SiO2/MgO/MgCl2)•TiClxZiegler-Natta Polyethylene Catalyst

“…[ 10 ] More recently, through the introduction of chromium species into this catalyst system, the catalytic properties were further improved. [ 24 ] Compared with these two catalysts, even better catalytic performance is expected for the novel vanadium-modifi ed (SiO 2 /MgO/MgCl 2 )·TiCl x ZN catalyst system.…”

“…In this work, TIBA was used as the cocatalyst because TIBA as the cocatalyst showed higher activity than TEA for the (SiO 2 /MgO/MgCl 2 )·TiCl x ZN catalyst as reported in our previous work. [ 10 ] The V-modifi ed ZN catalysts (MgV1:1/Ti, MgV5:1/Ti, and MgV10:1/Ti catalysts), Mg/Ti catalyst, and V/Ti catalyst were used in ethylene homopoly merization with different dosages of cocatalyst from 2.5 to 25 (Al/Ti molar ratio). Figure 1 showed the activities of the above catalysts.…”

“…Inspired by this report, we introduced amorphous porous silica to this system by reason of its high specifi c surface area with good morphology and successfully developed a novel (SiO 2 /MgO/MgCl 2 )·TiCl x ZN catalyst. [ 10 ] This novel catalyst without using relatively expensive and moisture-and/or air-sensitive compounds as starting Mg-sources could reduce the catalyst production cost and shows potential for application in commercial gas-phase polyolefi n processes. While based on the consideration of industrial application, the (SiO 2 /MgO/MgCl 2 )·TiCl x ZN catalyst still needs to be further improved in order to synthesize polymers with better performance.…”

Ethylene Polymerization over MgCl2/SiO2 Bi‐Supported Ziegler–Natta Hybrid Titanium/Vanadium Catalysts

“…In our previous work, Wang et al successfully developed a novel (SiO 2 /MgO/MgCl 2 )·TiCl x Ziegler–Natta catalyst for ethylene and ethylene/1‐hexene polymerization showing high activity, good hydrogen response, and copolymerization ability. The method was simple and cost‐effective …”

Heterogeneous Ziegler–Natta catalysts with various sizes of MgCl2 crystallites: synthesis and characterization

“…The reactor was constructed such that it could be placed in a centrifuge, where precipitate and liquid phase could be separated efficiently. An amount of Our procedure for synthesizing the Ziegler-Natta PE catalyst followed a typical industrial procedure that can be found in patented literature [17], and it also resembles procedures described in other publications [18,19] and to some extent the recipe provided by Wang et al [20]. The carrier synthesis described by Nakayama et al [21] is an example of a support material preparation that resembles the recipe used in this study.…”