Abstract: Processes for forming a polypropylene composition are provided herein comprising the steps of making a first propylene-based copolymer having a molecular weight distribution between 3 to 8.5, and making a second propylene-based polymer in the presence of the first propylene-based polymer to produce the polypropylene composition having a high molecular weight tail in the amount of between 1.0 wt. % and 10.0 wt. %. The polypropylene compositions produced have a broad molecular weight distribution and high molecular weight tail to provide improved stiffness while retaining toughness.

Abstract: Provided are methods for producing bimodal polyolefins comprising the steps of contacting ?-olefin monomers with a catalyst in slurry polymerization conditions in the presence of zero to minimum hydrogen to produce a high molecular weight polyolefin and contacting additional ?-olefin monomers in gas phase polymerization conditions and the high molecular weight polyolefin and the catalyst to produce bimodal polyolefin having high stiffness and broad molecular weight distribution. An additional step of polymerizing the bimodal polyolefin with a comonomer in a second gas phase can provide a bimodal impact copolymer having high stiffness and broad molecular weight distribution. Among the advantages of the present methods, bimodal polyolefins can be produced in a continuous process between a slurry polymerization reactor and a gas phase polymerization reactor without a venting step in between and with minimal hydrogen in the slurry polymerization reactor.

Abstract: A process of polymerizing olefins comprising combining propylene with a polymerization catalyst, hydrogen, and at least one external electron donor, such as at least one amino-silane donor, to form polypropylene in a first polymerization medium under solution or slurry conditions at or below the bubble point; removing hydrogen from the first polymerization medium and providing a first olefin/polyolefin separation step to form a second polymerization medium; transferring the second polymerization medium to a gas phase reactor and further combining with ethylene; obtaining a propylene-based impact copolymer. The propylene-based impact copolymer desirably has a melt flow rate of at least 60 g/10 min and is useful in automotive components.

Abstract: Disclosed is a method for polymerizing olefins comprising passing a heterogeneous single-site catalyst to a solution or slurry polymerization reactor in the absence of pre-polymerization, wherein the polymerization reactor operates at a temperature of at least 50° C. The heterogeneous single-site catalyst may be suspended and/or dissolved in a solvent selected from the group consisting of oils, aliphatic hydrocarbons and mixtures thereof. Also, the heterogeneous single-site catalyst may be passed to the polymerization reactor at a velocity of greater than 1 m/s or 3 m/s.

Abstract: A process for reducing the level of hydrogen in certain polymerization effluent and recycle streams containing unreacted propylene monomers and hydrogen by contacting the streams with a hydrogenation catalyst so as to convert at least part of the propylene to the corresponding alkane. The process is particularly applicable to the effluent from a slurry polymerization reactor which has been used to produce a polypropylene homopolymer or copolymer having a first molecular weight and at least part of the effluent is to be supplied to a slurry polymerization reactor to produce a polypropylene homopolymer or copolymer having a second, higher molecular weight.

Abstract: A process of polymerizing olefins comprising combining propylene with a polymerization catalyst, hydrogen, and at least one external electron donor, such as at least one amino-silane donor, to form polypropylene in a first polymerization medium under solution or slurry conditions at or below the bubble point; removing hydrogen from the first polymerization medium and providing a first olefin/polyolefin separation step to form a second polymerization medium; transferring the second polymerization medium to a gas phase reactor and further combining with ethylene; obtaining a propylene-based impact copolymer. The propylene-based impact copolymer desirably has a melt flow rate of at least 60 g/10 min and is useful in automotive components.

Abstract: Disclosed is a method of reducing and/or regulating the level of hydrogen in a polymerization reactor comprising contacting a first feed comprising a first amount of hydrogen with a hydrogenation catalyst prior to entering a polymerization reactor to form a second feed; then contacting the second feed having a second amount of hydrogen with monomers and a polymerization catalyst in a polymerization reactor to form a polymer. The first and second feeds may reside in a feed line from one reactor to another, a monomer feed line to the reactor, or in a recycle line to and from the same reactor.

Abstract: Disclosed is a method for polymerizing olefins comprising passing a heterogeneous single-site catalyst to a solution or slurry polymerization reactor in the absence of pre-polymerization, wherein the polymerization reactor operates at a temperature of at least 50° C. The heterogeneous single-site catalyst may be suspended and/or dissolved in a solvent selected from the group consisting of oils, aliphatic hydrocarbons and mixtures thereof. Also, the heterogeneous single-site catalyst may be passed to the polymerization reactor at a velocity of greater than 1 m/s or 3 m/s.

Abstract: A process for reducing the level of hydrogen in certain polymerization effluent and recycle streams containing unreacted propylene monomers and hydrogen by contacting the streams with a hydrogenation catalyst so as to convert at least part of the propylene to the corresponding alkane. The process is particularly applicable to the effluent from a slurry polymerization reactor which has been used to produce a polypropylene homopolymer or copolymer having a first molecular weight and at least part of the effluent is to be supplied to a slurry polymerization reactor to produce a polypropylene homopolymer or copolymer having a second, higher molecular weight.

Abstract: Disclosed is a method of reducing and/or regulating the level of hydrogen in a polymerization reactor comprising contacting a first feed comprising a first amount of hydrogen with a hydrogenation catalyst prior to entering a polymerization reactor to form a second feed; then contacting the second feed having a second amount of hydrogen with monomers and a polymerization catalyst in a polymerization reactor to form a polymer. The first and second feeds may reside in a feed line from one reactor to another, a monomer feed line to the reactor, or in a recycle line to and from the same reactor.