Methods of preparing a polymerization catalyst component is provided, in which a magnesium component, a Lewis acid solubilizing component, a titanium compound, optionally a transition metal compound different than the titanium compound, and typically an inert filler are combined in a slurrying agent and spray-dried to produce a catalyst precursor in the form of a substantially spherical and porous solid particle. The methods and catalysts of this disclosure can provide ethylene homopolymer and copolymer resins having a high molecular weight tail and a broadened molecular weight distribution as compared to more traditional Ziegler-Natta catalysts.

The present invention relates to a process for continuously producing an ultra-high molecular weight polyethylene by the ethylene slurry polymerization, wherein raw materials containing ethylene and optionally at least one comonomer are subjected to a continuous slurry polymerization in a hydrogen free atmosphere in the ethylene slurry polymerization condition by using 2-6 ethylene slurry polymerization reaction tanks connected in series, and the deviations of the polymerization temperatures, the polymerization pressures, and the gas phase compositions between the tanks each other are controlled to certain ranges. The ultra-high molecular weight polyethylene having the viscosity-average molecular weight of 150-800?10.sup.4 g/mol can be continuously produced. This process has flexible polymerization manner, large room for adjusting and controlling, and stable polymer performance. Moreover, the obtained ultra-high molecular weight polyethylene has low metal content, low ash content, and excellent mechanical properties.

The present invention relates to a process for continuously producing an ultra-high molecular weight polyethylene by the ethylene slurry polymerization, wherein raw materials containing ethylene and optionally at least one comonomer are subjected to a continuous slurry polymerization in a hydrogen free atmosphere in the ethylene slurry polymerization condition by using 2-6 ethylene slurry polymerization reaction tanks connected in series, and the deviations of the polymerization temperatures, the polymerization pressures, and the gas phase compositions between the tanks each other are controlled to certain ranges. The ultra-high molecular weight polyethylene having the viscosity-average molecular weight of 150-800?10.sup.4 g/mol can be continuously produced. This process has flexible polymerization manner, large room for adjusting and controlling, and stable polymer performance. Moreover, the obtained ultra-high molecular weight polyethylene has low metal content, low ash content, and excellent mechanical properties.

Graphene oxide (GO)/silica (SiO.sub.2) supported Ziegler-Natta (Z-N) catalysts are described. The catalyst includes a Z-N catalyst attached to a GO/SiO.sub.2 support. The GO/SiO.sub.2 support has a weight ratio of GO:SiO.sub.2 of greater than 1:5 and includes least 25 mol. % oxygen (O) atoms. Methods of making the catalyst and use of the catalyst in alpha-olefin polymerisation reactions are also described.

An activated solid catalyst component is disclosed formed from a magnesium compound, a titanium compound, an organosilicon compound, a supportive electron donor, and at least one internal electron donor. The solid catalyst component is activated to include titanium and carbon bonds by reaction with an activation agent, such as an aluminum compound. In one embodiment, small amounts of polymer are polymerized with the catalyst component during activation. The activated catalyst component is stable and, when formed, can later be used to produce various polyolefin polymers. The activated catalyst component has controlled reaction kinetics so that the catalyst does not overheat and degrade during initial polymerization.

An activated solid catalyst component is disclosed formed from a magnesium compound, a titanium compound, an organosilicon compound, a supportive electron donor, and at least one internal electron donor. The solid catalyst component is activated to include titanium and carbon bonds by reaction with an activation agent, such as an aluminum compound. In one embodiment, small amounts of polymer are polymerized with the catalyst component during activation. The activated catalyst component is stable and, when formed, can later be used to produce various polyolefin polymers. The activated catalyst component has controlled reaction kinetics so that the catalyst does not overheat and degrade during initial polymerization.

The present invention provides an ethylene polymer having a viscosity average molecular weight of 10010.sup.4 or more and 1,00010.sup.4 or less, in which a ratio between an isothermal crystallization time at 125 C. and an isothermal crystallization time at 123 C. obtained under specific isothermal crystallization time measurement conditions is 3.5 or more and 10.0 or less, and a degree of crystallization obtained using a differential scanning calorimeter (DSC) is 40% or more and 75% or less.

The present invention provides an ethylene polymer having a viscosity average molecular weight of 10010.sup.4 or more and 1,00010.sup.4 or less, in which a ratio between an isothermal crystallization time at 125 C. and an isothermal crystallization time at 123 C. obtained under specific isothermal crystallization time measurement conditions is 3.5 or more and 10.0 or less, and a degree of crystallization obtained using a differential scanning calorimeter (DSC) is 40% or more and 75% or less.

The present invention relates to an ethylene polymer and a process for preparing the same, wherein the ethylene polymer has an average particle size of 50-3000 ?m, a bulk density of 0.28-0.55 g/cm.sup.3, a true density of 0.930-0.980 g/cm.sup.3, a melt index at a load of 2.16 Kg at 190? C. of 0.01-2500 g/10 min, a crystallinity of 30-90%, a melting point of 105-147? C., a comonomer molar insertion rate of 0.01-5 mol %, a weight-average molecular weight of 2?10.sup.4 g/mol-40?10.sup.4 g/mol, and a molecular weight distribution of 1.8-10. In the preparation process, raw materials containing ethylene, hydrogen gas and a comonomer are subjected to a tank-type slurry polymerization with an alkane solvent having a boiling point of 5-55? C. or a mixed alkane solvent having a saturated vapor pressure of 20-150 KPa at 20? C. as the polymerization solvent in the presence of a polyethylene catalytic system, at the molar ratio of hydrogen gas to ethylene of 0.01-20:1, preferably 0.015-10:1, at the molar ratio of hydrogen gas to the comonomer of 0.1-30:1, preferably 0.15-25:1 to prepare the ethylene polymer.

The present invention relates to an ethylene polymer and a process for preparing the same, wherein the ethylene polymer has an average particle size of 50-3000 ?m, a bulk density of 0.28-0.55 g/cm.sup.3, a true density of 0.930-0.980 g/cm.sup.3, a melt index at a load of 2.16 Kg at 190? C. of 0.01-2500 g/10 min, a crystallinity of 30-90%, a melting point of 105-147? C., a comonomer molar insertion rate of 0.01-5 mol %, a weight-average molecular weight of 2?10.sup.4 g/mol-40?10.sup.4 g/mol, and a molecular weight distribution of 1.8-10. In the preparation process, raw materials containing ethylene, hydrogen gas and a comonomer are subjected to a tank-type slurry polymerization with an alkane solvent having a boiling point of 5-55? C. or a mixed alkane solvent having a saturated vapor pressure of 20-150 KPa at 20? C. as the polymerization solvent in the presence of a polyethylene catalytic system, at the molar ratio of hydrogen gas to ethylene of 0.01-20:1, preferably 0.015-10:1, at the molar ratio of hydrogen gas to the comonomer of 0.1-30:1, preferably 0.15-25:1 to prepare the ethylene polymer.