Abstract: The invention discloses a process for preparing high-performance propylene polymers, the process utilizing a high activity, highly stereoselective Ziegler-Natta catalyst and two or more stages of polymerization carried out under different hydrogen concentrations to prepare propylene polymers having broad molecular weight distribution, wherein non-uniformness of isotacticity of molecular chains of the final propylene polymers is improved by adjusting or controlling stereoselectivity of catalytic active sites under different hydrogen concentrations, namely, making the low molecular weight fraction of the polymers having a higher isotacticity and making the high molecular weight fraction of the polymers having a lower isotacticity, thereby overcoming the drawbacks of the propylene polymers having broad molecular weight distribution known in the art. The resulting final polymers have excellent combined properties, in particular, remarkably improved mechanical properties.

Abstract: Disclosed herein are a polypropylene with narrow molecular weight distribution and a process for preparing the same in a reactor using a Ziegler-Natta catalyst.

Abstract: A polyethylene composition comprising an ethylene/?-olefin copolymerized linear low density polyethylene, wherein the polyethylene composition has a Mw of from 100,000 g/mol to 200,000 g/mol, a Mw/Mn of from 4.0 to 9.0, a Mz/Mw of from 4.0 to 7.0, and a Mz+1/Mw of from 4.5 to 13.5, is provided. A film formed of the polyethylene composition is also provided.

Abstract: Disclosed herein is a polymerization method of propylene, which can prepare a propylene homopolymer with both high fluidity and high rigidity as well as a propylene/?-define copolymer having both high fluidity and a good rigidity-toughness balance by, for example, control of polymerization steps and elevation of polymerization temperature, while the catalyst still maintains a relatively high polymerization activity.

Abstract: A polyethylene composition comprising an ethylene/?-olefin copolymerized linear low density polyethylene, wherein the polyethylene composition has a Mw of from 100,000 g/mol to 200,000 g/mol, a Mw/Mn of from 4.0 to 9.0, a Mz/Mw of from 4.0 to 7.0, and a Mz+1/Mw of from 4.5 to 13.5, is provided. A film formed of the polyethylene composition is also provided.

Abstract: The invention discloses a process for preparing high-performance propylene polymers, the process utilizing a high activity, highly stereoselective Ziegler-Natta catalyst and two or more stages of polymerization carried out under different hydrogen concentrations to prepare propylene polymers having broad molecular weight distribution, wherein non-uniformness of isotacticity of molecular chains of the final propylene polymers is improved by adjusting or controlling stereoselectivity of catalytic active sites under different hydrogen concentrations, namely, making the low molecular weight fraction of the polymers having a higher isotacticity and making the high molecular weight fraction of the polymers having a lower isotacticity, thereby overcoming the drawbacks of the propylene polymers having broad molecular weight distribution known in the art. The resulting final polymers have excellent combined properties, in particular, remarkably improved mechanical properties.

Abstract: The present invention provides a process for preparing high melt strength propylene polymer by direct polymerization, comprising that a propylene polymer with wide molecular weight distribution and containing “very high molecular weight fraction” can be prepared by controlling the species and ratios of the external electron donors in the Ziegler-Natta catalyst system at different reaction stages according to the requirement for different molecular weight fractions in the different propylene polymerization stage of the series operation, and said polymer has excellent mechanical properties, especially with very high melt strength. The present invention also provides a propylene homopolymer with high melt strength, comprising the following features: (1) the MFR is 0.2-10 g/10 min at 230° C. with a load of 2.16 kg; (2) the molecular weight distribution Mw/Mn is 6-20; (3) the content of the fraction with a molecular weight higher than 5,000,000 is higher than or equal to 0.

Abstract: Disclosed herein is a polymerization method of propylene, which can prepare a propylene homopolymer with both high fluidity and high rigidity as well as a propylene/?-define copolymer having both high fluidity and a good rigidity-toughness balance by, for example, control of polymerization steps and elevation of polymerization temperature, while the catalyst still maintains a relatively high polymerization activity.

Abstract: Disclosed herein are a polypropylene with narrow molecular weight distribution and a process for preparing the same in a reactor using a Ziegler-Natta catalyst.

Abstract: The present invention provides a process for preparing high melt strength propylene polymer by direct polymerization, comprising that a propylene polymer with wide molecular weight distribution and containing “very high molecular weight fraction” can be prepared by controlling the species and ratios of the external electron donors in the Ziegler-Natta catalyst system at different reaction stages according to the requirment for different molecular weight fractions in the different propylene polymerization stage of the series operation, and said polymer has excellent mechnical properties, especially with very high melt strength. The present invention also provides a propylene homopolymer with high melt strength, comprising the following features: (1) the MFR is 0.2-10 g/10 min at 230° C. with a load of 2.16 kg; (2) the molecular weight distribution Mw/Mn is 6-20; (3) the content of the fraction with a molecular weight higher than 5,000,000 is higher than or equal to 0.

Abstract: The invention discloses a process for preparing high-performance propylene polymers, the process utilizing a high activity, highly stereoselective Ziegler-Natta catalyst and two or more stages of polymerization carried out under different hydrogen concentrations to prepare propylene polymers having broad molecular weight distribution, wherein non-unifomess of isotacticity of molecular chains of the final propylene polymers is improved by adjusting or controlling stereoselectivity of catalytic active sites under different hydrogen concentrations, namely, making the low molecular weight fraction of the polymers having a higher isotacticity and making the high molecular weight fraction of the polymers having a lower isotacticity, thereby overcoming the drawbacks of the propylene polymers having broad molecular weight distribution known in the art. The resulting final polymers have excellent combined properties, in particular, remarkably improved mechanical properties.

Abstract: The present invention provides a propylene polymer composition for producing a biaxially oriented film, comprising propylene random copolymer and propylene homopolymer; wherein the propylene random copolymer is a copolymer of propylene and ethylene, optionally comprising one or more alpha-olefins of C4-C10; the propylene polymer composition has an overall isotacticity index, as determined by nuclear magnetic resonance method, of greater than or equal to 96.5%, and an ethylene content of greater than 0.3 wt %; and wherein, the melt flow rate of the propylene random copolymer is lower than that of the propylene homopolymer. The biaxially oriented polypropylene film produced by the propylene polymer composition of the present invention exhibits excellent physical properties, and has, in the absence of any stiffening agent, relatively higher modulus and stiffness.

Abstract: The present invention provides a propylene polymer composition for producing a biaxially oriented film, comprising propylene random copolymer and propylene homopolymer; wherein the propylene random copolymer is a copolymer of propylene and ethylene, optionally comprising one or more alpha-olefins of C4-C10; the propylene polymer composition has an overall isotacticity index, as determined by nuclear magnetic resonance method, of greater than or equal to 96.5%, and an ethylene content of greater than 0.3 wt %; and wherein, the melt flow rate of the propylene random copolymer is lower than that of the propylene homopolymer. The biaxially oriented polypropylene film produced by the propylene polymer composition of the present invention exhibits excellent physical properties, and has, in the absence of any stiffening agent, relatively higher modulus and stiffness.

Abstract: The present invention is to provide a composite carrier, which is spheric particles obtainable by contacting magnesium halide with one or more electron donor compounds to form a solution, then mixing the solution with silica material having an average particle size of less than 10 microns to form a mixture, and drying the mixture through spray drying process. The present invention is also to provide a catalyst component comprising said composite carrier. When the catalyst component is used together with a cocatalyst component in propylene polymerization, it exhibits higher polymerization activity and stereospecificity, and can be used to prepare high impact resistent ethylene-propylene copolymer having high ethylene content.

Abstract: The present invention is to provide a composite carrier, which is spheric particles obtainable by contacting magnesium halide with one or more electron donor compounds to form a solution, then mixing the solution with silica material having an average particle size of less than 10 microns to form a mixture, and drying the mixture through spray drying process. The present invention is also to provide a catalyst component comprising said composite carrier. When the catalyst component is used together with a cocatalyst component in propylene polymerization, it exhibits higher polymerization activity and stereospecificity, and can be used to prepare high impact resistant ethylene-propylene copolymer having high ethylene content.