The present invention relates to a polyethylene homo- or copolymer having improved wear properties. In particular, the invention relates to an ultra-high molecular weight polyethylene having improved wear properties prepared using a heterogeneous Ziegler catalyst system. Said polyethylene homo- or copolymer is characterized in that the abrasion index of said polyethylene is related to the elongational stress according to the formula (I): in which ES=elongational stress as measured according to ISO 11542-2:1998 AI=abrasion index, as measured according to ISO 15527:2010 where the reference material according to ISO 15527:2010 is set to 100; β<1.8; and −0.015<a<−0.017.

[00001]$\begin{array}{cc}\mathrm{AI}<\frac{\mathrm{ES}-\beta }{\alpha }& \left(I\right)\end{array}$

A hydrogel comprising water, and a plurality of titanium-silica nanoparticle agglomerates, wherein each titanium-silica nanoparticle agglomerate is an agglomeration of titanium-silica nanoparticles, the agglomerates having an average titanium loading designated x with a coefficient of variation for the average titanium loading of less than about 1.0, wherein a silica content of the hydrogel is of from about 10 wt. % to about 35 wt. % based on a total weight of the hydrogel.

The invention relates to a process for preparing a solid support for a procatalyst suitable for preparing a catalyst composition for olefin polymerization, said process for preparing said solid support comprising reacting a compound R.sup.4.sub.zMgX.sup.4.sub.2-z with a silane compound Si(OR.sup.5).sub.4-n(R.sup.6).sub.n in a solvent and mixing the resulting mixture with a mixing device and at a certain mixing speed in order to give a solid support Mg(OR.sup.1).sub.xX.sup.1.sub.2-x said solid support obtained having an average particle size of at most 17 μm, preferably at most 16 or 14 μm, more preferably at most 12 μm. The invention further relates to a solid support, a process for preparing a procatalyst and said procatalyst as well as polyolefins obtained using said procatalyst.

The present disclosure provides a ziegler-natta pro-catalyst composition for the polymerization of propylene to produce polypropylene with reduced polymer-fines.

The invention relates to a continuous process for the production of ultra-high molecular weight polyethylene with an Elongational Stress of at least 0.43 N/mm.sup.2. The polymerisation of ethylene takes place in the presence of a catalyst and hydrogen. It is an advantage of the process according to the invention that the use of small amounts of hydrogen during the production of UHM-WPE reduces reactor fouling. Furthermore, the process according to the invention results in longer run times in polymerization reactors, less cleaning cycles to remove reactor fouling and in less need for other anti-fouling agents or anti-static agents.

Modified chromium-based catalyst compositions for olefin polymerization are disclosed. The modifiers prevent or reduce catalyst particle aggregation providing improved catalyst particle dispersion and consistent flow index response of the compositions in olefin polymerization.

This invention relates to heterophasic copolymers of propylene and an alpha olefin comonomer having a high fill phase content (≧15%), and heterophasic polymerization processes using a single site catalyst system with a support having high average particle size (PS≧30 μm), high surface area (SA≧400 m.sup.2/g), low pore volume (PV≦2 mL/g), and a mean pore diameter range of 1≦PD≦20 nm.

The invention relates to a catalyst composition for the polymerization of olefins, in which the catalyst is produced using a metal-containing compound having the formula (I): MeR.sub.nX.sub.3-n (I), in which X is a halogen, Me is a metal of group III of Mendelejev's Periodic Table of Elements, R is a hydrocarbon moiety comprising>2 carbon atoms, and n is 1≦n<3, or a dimer of a compound of formula (I); and the average particle size of the catalyst as reflected by D.sub.50 (measured according to ISO13320) is between 0.5 and 4.5 μηη. The invention also relates to a process for production of said catalyst composition. The invention further relates to ultra-high molecular weight polyethylene produced via a polymerization process using said catalyst composition.

Supported chromium catalysts with an average valence less than +6 and having a hydrocarbon-containing or halogenated hydrocarbon-containing ligand attached to at least one bonding site on the chromium are disclosed, as well as ethylene-based polymers with terminal alkane, aromatic, or halogenated hydrocarbon chain ends. Another ethylene polymer characterized by at least 2 wt. % of the polymer having a molecular weight greater than 1,000,000 g/mol and at least 1.5 wt. % of the polymer having a molecular weight less than 1000 g/mol is provided, as well as an ethylene homopolymer with at least 3.5 methyl short chain branches and less than 0.6 butyl short chain branches per 1000 total carbon atoms.

This invention relates to high porosity (≧15%) and/or low pore diameter (PD<165 μm) propylene polymers and propylene polymerization processes using single site catalyst systems with supports having high surface area (SA≧400 m.sup.2/g), low pore volume (PV≦2 mL/g), a specific mean pore diameter range (PD=1-20 nm), and high average particle size (PS≧30 μm).