An ultra-high molecular weight, ultra-fine particle size polyethylene has a viscosity average molecular weight (Mv) greater than 1×10.sup.6. The polyethylene is spherical or are sphere-like particles having a mean particle size of 10-100 μm, having a standard deviation of 2-15 μm and a bulk density of 0.1-0.3 g/mL. Using the polyethylene as a basic polyethylene, a grafted polyethylene can be obtained by means of a solid-phase grafting method; and a glass fiber-reinforced polyethylene composition comprising the polyethylene and glass fibers, and a sheet or pipe prepared therefrom; a solubilized ultra-high molecular weight, ultra-fine particle size polyethylene; and a fiber and a film prepared from the solubilized ultra-high molecular weight, ultra-fine particle size polyethylene may also be obtained. The method has simple steps, is easy to control, has a relatively low cost and a high repeatability, and can realize industrialisation.

A method for preparing an olefin-olefinic alcohol copolymer and an olefin-olefinic alcohol copolymer prepared by the method are provided. The catalyst used in the method for preparing the olefin-olefinic alcohol copolymer has a diimine metal complex as shown in Formula I.

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A method for preparing an olefin-olefinic alcohol copolymer and an olefin-olefinic alcohol copolymer prepared by the method are provided. The catalyst used in the method for preparing the olefin-olefinic alcohol copolymer has a diimine metal complex as shown in Formula I.

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A slurry polymerization process for the preparation of polyethylene in a reactor cascade of two or more polymerization reactors wherein monomers are polymerized in the polymerization reactors which include a reactor outlet arranged in each reactor bottom for feeding a reactor slurry to a subsequent polymerization reactor and for emptying the polymerization reactor.

A slurry polymerization process for the preparation of polyethylene in a reactor cascade of two or more polymerization reactors wherein monomers are polymerized in the polymerization reactors which include a reactor outlet arranged in each reactor bottom for feeding a reactor slurry to a subsequent polymerization reactor and for emptying the polymerization reactor.

Embodiments of the present disclosure are directed towards catalyst formulations including a metallocene and a stearic compound selected from bis 2-hydroxyethyl stearyl amine, aluminum distearate, and combinations thereof, where the metallocene is represented by the following formula: (Formula (I)) wherein each n-PR is n-propyl, and each X is independently CH.sub.3, Cl, or F. ##STR00001##

Embodiments of the present disclosure are directed towards catalyst formulations including a metallocene and a stearic compound selected from bis 2-hydroxyethyl stearyl amine, aluminum distearate, and combinations thereof, where the metallocene is represented by the following formula: (Formula (I)) wherein each n-PR is n-propyl, and each X is independently CH.sub.3, Cl, or F. ##STR00001##

Provided is a polyethylene powder having a density of 910 kg/m.sup.3 or more and less than 935 kg/m.sup.3 and an average particle diameter of 50 μm or more and less than 140 μm, wherein the polyethylene powder contains a particle having a particle diameter of 60 μm and a particle having a particle diameter of 100 μm, the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 2.0 MPa or more and less than 5.0 MPa, and the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 0.5 times or more and less than 1.3 times the compressive strength at 10% displacement of the particle having a particle diameter of 100 μm.

Provided is a polyethylene powder having a density of 910 kg/m.sup.3 or more and less than 935 kg/m.sup.3 and an average particle diameter of 50 μm or more and less than 140 μm, wherein the polyethylene powder contains a particle having a particle diameter of 60 μm and a particle having a particle diameter of 100 μm, the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 2.0 MPa or more and less than 5.0 MPa, and the compressive strength at 10% displacement of the particle having a particle diameter of 60 μm is 0.5 times or more and less than 1.3 times the compressive strength at 10% displacement of the particle having a particle diameter of 100 μm.

The present invention relates to a vinyl chloride polymer and a production method thereof. More specifically, the present invention provides a vinyl chloride polymer having a polydispersity index of 2.0 to 2.3 and a porosity of 60% or greater and a production method thereof in which a vinyl chloride polymerization seed having a conversion rate of 5-20% is first prepared through preliminary polymerization and then a vinyl chloride monomer is introduced into the vinyl chloride polymerization seed to polymerize (main polymerization) a vinyl chloride polymer.