The present disclosure relates to a polyethylene composition capable of producing a molded product having excellent environmental stress crack resistance, and improving total volatile organic compound (TVOC) properties that can be generated by a low molecular weight polymer, and a method for preparing the same.

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.

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.

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.

Embodiments of the present disclosure directed towards titanium biphenylphenol polymerization precatalysts of Formula (I).

Embodiments of the present disclosure directed towards titanium biphenylphenol polymerization precatalysts of Formula (I).

A metallocene compound having a structure shown by formula (I). A functional group connected to a bridging atom of the metallocene compound is an amine-substituted group and/or a metallocene-substituted group and/or a substituted metallocene group. A metallocene catalyst containing the metallocene compound has high catalytic activity, and can synthesize metallocene polypropylene having high isotacticity.

R.sup.IR.sup.IIZ(Cp.sup.III).sub.n(E).sub.2-nML.sup.IVL.sup.V   (I)

Activators may comprise compounds represented by the Formula [Ar(EHR.sup.1R.sup.2)(OR.sup.3)]d+[M.sup.k+Q.sub.n].sup.d, wherein: Ar is an aryl group; E is nitrogen or phosphorous; R.sup.1 is a C.sub.1-C.sub.30, optionally substituted, linear alkyl group; R.sup.2 is a C.sub.1-C.sub.30, optionally substituted, linear alkyl group; R.sup.3 is a C.sub.10-C.sub.30, optionally substituted, linear alkyl group; M is an element selected from group 13 of the Periodic Table of the Elements; d is 1, 2 or 3; k is 1, 2, or 3; n is 1, 2, 3, 4, 5, or 6; n−k=d; and each Q is independently hydride, bridged or unbridged dialkylamido, halide, alkoxide, aryloxide, hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, or halosubstituted-hydrocarbyl radical. Catalysts systems may comprise these activators and methods of preparing polyolefins may use these catalysts systems.

Activators may comprise compounds represented by the Formula [Ar(EHR.sup.1R.sup.2)(OR.sup.3)]d+[M.sup.k+Q.sub.n].sup.d, wherein: Ar is an aryl group; E is nitrogen or phosphorous; R.sup.1 is a C.sub.1-C.sub.30, optionally substituted, linear alkyl group; R.sup.2 is a C.sub.1-C.sub.30, optionally substituted, linear alkyl group; R.sup.3 is a C.sub.10-C.sub.30, optionally substituted, linear alkyl group; M is an element selected from group 13 of the Periodic Table of the Elements; d is 1, 2 or 3; k is 1, 2, or 3; n is 1, 2, 3, 4, 5, or 6; n−k=d; and each Q is independently hydride, bridged or unbridged dialkylamido, halide, alkoxide, aryloxide, hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, or halosubstituted-hydrocarbyl radical. Catalysts systems may comprise these activators and methods of preparing polyolefins may use these catalysts systems.

A nano platelet gibbsite treated with compound of formula (OR.sup.a).sub.3Si—R.sup.b or of formula R.sup.c—COOH wherein R.sup.a equal to or different from each other is a C.sub.1-C.sub.10 alkyl radical; R.sup.b is a C.sub.5-C.sub.30 hydrocarbon radical and R.sup.c is a C.sub.5-C.sub.30 hydrocarbon radical is used as a catalyst support.