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

The present disclosure relates to a porous solid adduct comprising magnesium chloride and ethanol, characterized by a relationship between the content of alcohol, average pore radius and amount of porosity deriving from pores with radii of 100-1000 nm, and catalyst components produced therefrom that are capable of producing polyolefins with increased porosity.

The present disclosure relates to a porous solid adduct comprising magnesium chloride and ethanol, characterized by a relationship between the content of alcohol, average pore radius and amount of porosity deriving from pores with radii of 100-1000 nm, and catalyst components produced therefrom that are capable of producing polyolefins with increased porosity.

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.

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.

This invention relates to compositions and medical devices comprising anti-microbial active particles, for inhibiting microbial growth. This invention further provides methods of making such compositions and medical devices.

A method including contacting a chromium-based catalyst with a reducing agent in a solvent to lower an oxidation state of at least some chromium in the chromium-based catalyst to give a reduced chromium-based catalyst, drying the reduced chromium-based catalyst at a temperature, and adjusting the temperature to affect the flow index response of the reduced chromium-based catalyst.

A method including contacting a chromium-based catalyst with a reducing agent in a solvent to lower an oxidation state of at least some chromium in the chromium-based catalyst to give a reduced chromium-based catalyst, drying the reduced chromium-based catalyst at a temperature, and adjusting the temperature to affect the flow index response of the reduced chromium-based catalyst.

The present invention deals with a process for polymerising ethylene in the presence of an olefin polymerisation catalyst comprising titanium, magnesium and halogen in at least one polymerisation stage where ethylene is polymerised in slurry, the process comprising treating the polymerisation catalyst in a pre-treatment step by polymerising an olefin on the polymerisation catalyst so that the ratio of the weight of the olefin polymer to the weight of the original solid catalyst component is from 0.1 to 10 g/g and using the pre-treated catalyst in the production of ultra-high molecular weight polyethylene.

The present invention deals with a process for polymerising ethylene in the presence of an olefin polymerisation catalyst comprising titanium, magnesium and halogen in at least one polymerisation stage where ethylene is polymerised in slurry, the process comprising treating the polymerisation catalyst in a pre-treatment step by polymerising an olefin on the polymerisation catalyst so that the ratio of the weight of the olefin polymer to the weight of the original solid catalyst component is from 0.1 to 10 g/g and using the pre-treated catalyst in the production of ultra-high molecular weight polyethylene.