Abstract: This present disclosure relates to catalytic processes for oligomerizing bio-based olefinic mixtures to higher value renewable fuels via a doped Chabazite zeolite catalyst. A stream including a C2-C8 olefin and an oxygenate is fed to an oligomerization process utilizing a doped Chabazite zeolite catalyst resulting in high yields and selectivity of oligomers used to produce bio-based jet fuel and/or diesel fuels depending upon reaction temperatures and pressures. The process also produces iso-octane that is suitable for producing bio-based gasoline. The process tolerates relatively high levels of oxygenates in the olefinic feed and the catalyst is capable of air regeneration.

Abstract: The present invention relates to a propylene polymerizing solid catalyst for reducing the volatile organic compound (VOC) and a method of producing polypropylene using the propylene polymerizing solid catalyst, the propylene polymerizing solid catalyst including an organic electron donor formed of a combination of a first internal electron donor of titanium, magnesium, halogen and cyclic diester and a second internal electron donor of diether, and has improved hydrogen reactivity of a catalyst compared to a conventional method and has an effect that is capable of producing an eco-friendly polypropylene which has greatly lowered a content of the VOC by using the catalyst.

Abstract: A high density, high polydispersity polyethylene having improved properties, and a process of producing same.

Abstract: A method comprising introducing a polymerization feed comprising an ?-olefin, a diluent, and a diene to a polymerization system, under polymerization conditions, whereby a polymer product is produced, wherein the diene is present at a level in the range of from about 1 ppm to about 1000 ppm based on the diluent.

Abstract: In a process for producing polyethylene having a molecular weight of at least 3×105 g/mol as determined by ASTM 4020, ethylene is contacted under polymerization conditions with a slurry of a catalyst composition in at least one hydrocarbon. The catalyst composition comprises a Group 4 metal complex of a phenolate ether ligand and the slurry includes from about 5 to less than 40 ppm per liter of a compound effective to increase the conductivity of said at least one hydrocarbon.

Abstract: Living radical polymerization processes, reaction products of such processes, and compositions containing such reaction products are provided. More particularly, a living radical polymerization of (meth)acrylic acid monomers employing having a defined order of introduction of the reactants and/or a specific set of reaction conditions, is provided.

Abstract: A process comprising contacting a catalyst system with one or more olefins in a bubble column reactor. Also, a polyolefin copolymer composition comprising ethylene, propylene and optionally a C4 to C20 alpha olefin; said composition having a bimodal distribution with respect to composition distribution, molecular weight distribution or a combination thereof; an Mw of 10,000 g/mol or more; and/or at least two melting peaks in a DSC heating cycle with a difference in melting temperatures of at least 5° C.

Abstract: A slurry process for the polymerisation of ethylene is disclosed, which takes place in a reactor system comprising one or more reactors in series, having a characteristic such that the average polymerisation productivity [kg PE/kgcata] per unit ethylene per hour aI during operation at any first residence time rI is less than 1.7 (a2r2 ?aIrI)/(r2?rI), where a2 is the average polymerisation productivity [kgPE/kgcata] per unit ethylene per hour during operation at any second residence time r2 where r2>rI, a2 and r2 being measured either in the same reactor in the case of a single reactor polymerisation, or in a reactor subsequent to the reactor in which aI and rI are measured in the case where the polymerisation takes place in more than one reactor, and wherein the specific yield of the reactor system is greater than 0.

Abstract: Living radical polymerization processes, reaction products of such processes, and compositions containing such reaction products are provided. More particularly, a living radical polymerization of (meth)acrylic acid monomers employing having a defined order of introduction of the reactants and/or a specific set of reaction conditions, is provided.

Abstract: Polymerization reactor systems providing real-time control of the average particle size of catalyst system components are disclosed. Methods for operating such polymerization reactor systems also are described.

Abstract: Process for preparing polymers by controlled free-radical polymerization, wherein the polymerization of one or more free-radically polymerizable monomers of the general formula (I) where R1, R2, R3 are each H, C1-C4-alkyl, R4 is C(?O)0R5, C(?O)NHR15, C(?O)NR5R6, OC(?O)CH3, C(?O)OH, CN, aryl, hetaryl, C(?O)OR5OH, C(?O)OR5Si(OR5)3, halogen, NHC(O)H, P(?O)(OR7)2, R5 is C1-C20-alkyl, R15 is C1-C20-alkyl, R6 is C1-C20-alkyl, R7 is H, C1-C20-alkyl, in the presence of a. one or more catalysts comprising Cu in the form of Cu(0), Cu(I), Cu(II) or mixtures thereof, b. one or more initiators selected from the group consisting of organic halides or pseudohalides, c. one or more ligands, d. optionally one or more solvents, e. optionally one or more inorganic halide salts, and comprises the steps i) addition of the catalyst a., ii) optionally addition of monomers of the general formula (I), iii) optionally addition of solvent d., iv) addition of ligand c., v) addition of initiator b.

Abstract: A method comprising contacting an olefin in the presence of a catalyst and a melt index modifier (MIM) under conditions suitable to form a polyolefin and recovering the polyolefin, wherein the polyolefin melt index is increased by at least about 25%, wherein the normalized catalyst activity is decreased by less than about 10%, and wherein the MIM is characterized by the general formula R1—HC?CH—R2 or R3R4C?CH2 where R1, R2, R3, R4 are each selected from the group consisting of a non-aromatic organyl group.

Abstract: A polymerization process for copolymerizing ethylene and a series of ?-olefins to form a branched polyethylene, in which the series of ?-olefins is generated in-situ by an ethylene oligomerization catalyst, is improved if the oligomerization catalyst has a Schulz-Flory constant of about 0.30 to about 0.55. This makes very little higher molecular weight ?-olefins, which allows for easy removal of unpolymerized ?-olefins from the polyolefin product.

Abstract: The invention relates to a process for the synthesis of a Ziegler Natta procatalyst, the process comprising first treating magnesium alkoxide with a twice used mixed solvent of TiCl4 and chlorobenzene to form a first stage product, then treating the first stage product with a once used mixed solvent of TiCl4 and chlorobenzene to form a second stage product and finally treating the second stage product with mixed solvent recovered by treatment of effluent from the first treatment with benzoyl chloride so as to convert contaminant of formula TiCl3OR in the effluent to an addition complex which is precipitated, filtered off and hydrolyzed to recover ethyl benzoate and to form Ti(OH)4 as a side product, the product after final treatment being subjected to a plurality of successive washing steps with used as well as recovered hexane.

Abstract: A process for making an ethylene homopolymer in the presence of an oxide-supported chromium catalyst is disclosed. A small amount of an ?-olefin contacted with the catalyst before polymerizing ethylene or introduced into an ethylene homopolymerization unexpectedly boosts process productivity. When used at part per million levels, the ?-olefin improves productivity while maintaining desirable polymer properties. The invention is particularly valuable for making HDPE resins useful for blow molding applications.

Abstract: The present invention relates to superabsorbent polymer comprising the comprising the free radical polymerization product of an aqueous monomer mixture containing at least one ?,?-ethylenically unsaturated monomer; at least one monomer having at least two ?,?-ethylenically unsaturated groups; a crosslinking agent having at least two polymerizable double bonds; iron ions in an amount of from about 0.1 to about 3 wppm based on the total weight of the aqueous monomer mixture; and at least one chelating agent in an amount to provide a molar ratio of chelating agent to iron ion of from about 0.8 to about 4.0.

Abstract: The present invention relates to a catalytic composition for producing a 1-alkene-acrylate copolymer that includes a metal nano catalyst, and a method for producing a 1-alkene-acrylate copolymer. In the catalytic composition for producing a 1-alkene-acrylate copolymer, since the content of the polar comonomer is high, it may be used to produce the 1-alkene-acrylate copolymer that has no crystallinity and is capable of being used as an optical material. The method for producing the 1-alkene-acrylate copolymer may be produced by using a simple process of a mild polymerization condition without a polymerization condition of high temperature and high pressure, and it is easy to control physical properties.

Abstract: The present invention relates to process for the preparation of a superabsorbent polymer comprising the steps of a) subjecting an aqueous monomer mixture containing at least one ?,?-ethylenically unsaturated monomer; at least one monomer bearing at least two ?,?-ethylenically unsaturated groups; iron ions in an amount of 0.1 to 3 wppm based on the total weight of the aqueous monomer mixture; and at least one chelating agent in an amount to provide a mol ratio of chelating agent to iron ion of 0.8 to 4.0 to free radical polymerization in an reactor to obtain a super-absorbent polymer; and b) recovering the superabsorbent polymer, whereby if the process is continuous and is run in an agitated reactor the upper limit of the mol ratio of chelating agent to iron ion is 4.0 for a throughput of total reaction mixture through the reactor of at most 1.3 kg/h per liter reactor volume.

Abstract: The invention concerns catalysts comprising (i) a cladded catalyst support comprising (a) a core which comprises alumina particles and (b) about 1 to about 40 weight percent silica cladding, based on the weight of the cladded catalyst support, on the surface of the core; the catalyst support having a BET surface area of greater than 20 m2/g and a porosity of at least about 0.2 cc/g; and (ii) 0.1 to 10 weight percent, based on the weight of the catalyst, of catalytically active transition metal on the surface of the cladded catalyst support; wherein the catalyst support has a normalized sulfur uptake (NSU) of up to 25 ?g/m2. The invention also concerns the production and use of such catalysts.

Abstract: Disclosed herein are various processes, including continuous fluidized-bed gas-phase polymerization processes for making a high strength, high density polyethylene copolymer, comprising (including): contacting monomers that include ethylene and optionally at least one non-ethylene monomer with fluidized catalyst particles in a gas phase in the presence of hydrogen gas at an ethylene partial pressure of 100 psi or more and a polymerization temperature of 120° C. or less to produce a polyethylene copolymer having a density of 0.945 g/cc or more and an ESCR Index of 1.0 or more wherein the catalyst particles are prepared at an activation temperature of 700° C. or less, and include silica, chromium, and titanium.

Abstract: Of the many embodiments presented herein, one is a subterranean treatment fluid comprising: an aqueous fluid; and a water-soluble degradable synthetic vinyl polymer having a labile link in its backbone. Also provided in one instance is a water-soluble degradable synthetic vinyl polymer with labile group in its backbone made by a redox polymerization, the redox polymerization reaction comprising these reactants: a macroinitiator that comprises a labile link, an oxidizing metal ion, and a vinyl monomer.

Abstract: The present invention is directed to a composite particle that is microscopically two-dimensional with a third nanoscopic dimension, and to methods of making same. The particle may include a support and a metal layer. The metal layer may be catalytically active such that the particle is adapted to act as a catalyst.

Abstract: The present invention relates to process for the preparation of a superabsorbent polymer comprising the steps of a) subjecting an aqueous monomer mixture containing at least one ?,?-ethylenically unsaturated monomer; at least one monomer bearing at least two ?,?-ethylenically unsaturated groups; iron ions in an amount of 0.1 to 3 wppm based on the total weight of the aqueous monomer mixture; and at least one chelating agent in an amount to provide a mol ratio of chelating agent to iron ion of 0.8 to 4.0 to free radical polymerization in an reactor to obtain a super-absorbent polymer; and b) recovering the superabsorbent polymer, whereby if the process is continuous and is run in an agitated reactor the upper limit of the mol ratio of chelating agent to iron ion is 4.0 for a throughput of total reaction mixture through the reactor of at most 1.3 kg/h per liter reactor volume.

Abstract: The invention relates to a process for the synthesis of a Ziegler Natta procatalyst, the process comprising first treating magnesium alkoxide with a twice used mixed solvent of TiCl4 and chloro benzene to form a first stage product, then treating the first stage product with a once used mixed solvent of TiCl4 and chlorobenzene to form a second stage product and finally treating the second stage product with mixed solvent recovered by treatment of effluent from the first treatment with benzoyl chloride so as to convert contaminant of formula TiCl3OR in the effluent to an addition complex which is precipitated, filtered off and hydrolyzed to recover ethyl benzoate and to form Ti(OH)4 as a side product, the product after final treatment being subjected to a plurality of successive washing steps with used as well as recovered hexane.

Abstract: A process for the preparation of a catalyst that contains at least one modified zeolite, whereby said zeolite—before being modified—has a maximum pore opening diameter that is less than or equal to 7 ?, and whereby said process comprises at least: a) One stage for introducing at least one metal that is selected from among the metals of groups VIB and VIII of the periodic table on a substrate that is based on at least one protonated zeolite, b) One stage for treating said zeolite in the presence of at least one molecular compound that contains at least one silicon atom, and said compound that has a diameter that is greater than the maximum opening diameter of the pores of said zeolite, c) At least one heat treatment stage, is described.

Abstract: A coating solution comprising: a first solvent; 0.1 to 30 parts by weight of a polycarboxylic acid-based polymer relative to 100 parts by weight of the solvent; and 0.05 to 0.25 chemical equivalent of a zinc compound relative to an amount of carboxyl group in the polycarboxylic acid-based polymer, wherein a number average molecular weight of the polycarboxylic acid-based polymer is in a range of 40,000 to 10,000,000.

Abstract: Polyethylene is made by (co)polymerizing ethylene in a gas-phase reactor using a catalyst system comprising a chromium catalyst and a Group 4 transition metal catalyst, co-supported on an inorganic oxide support. The Group 4 transition metal catalyst is defined by the formula shown, wherein M is a Group 4 metal, PI is a phosphinimide or ketimide ligand (shown), L is a monoanionic ligand which is a cyclopentadienyl or a bulky heteroatom type ligand, m is 1 or 2, n is 0 or 1, and p is an integer. The co-supported catalyst system gives access to polyethylene having a broad or bimodal molecular weight distribution. In the copolymerization of ethylene, reversed or partially reversed comonomer distribution is achieved: the Group 4 component provides polymer segments having higher molecular weight and also higher comonomer incorporation than polymer segments produced at the chromium sites.

Abstract: A method of polymerizing poly(cyclic)olefin monomers encompassing (a) combining a monomer composition containing the poly(cyclic)olefin monomers, a non-olefinic chain transfer agent and an activator compound to faun a mixture; (b) heating the mixture; and (c) adding a polymerization catalyst containing Ni and/or Pd. The non-olefinic chain transfer agent includes one or more compounds selected from H2, alkylsilanes, alkylalkoxysilanes, alkylgermanes, alkylalkoxygermanes, alkylstannanes, and alkylalkoxystannanes. The activator is characterized as having an active hydrogen with a pKa of at least 5. The resulting poly(cyclic)olefin polymers can be used in photoresist compositions.

Abstract: Disclosed herein are various processes, including continuous fluidized-bed gas-phase polymerization processes for making a high strength, high density polyethylene copolymer, comprising (including): contacting monomers that include ethylene and optionally at least one non-ethylene monomer with fluidized catalyst particles in a gas phase in the presence of hydrogen gas at an ethylene partial pressure of 100 psi or more and a polymerization temperature of 105° C. or less to produce a polyethylene copolymer having a density of 0.945 g/cc or more and an ESCR Index of 1.0 or more wherein the catalyst particles are prepared at an activation temperature of 700° C. or less, and include silica, chromium, and titanium.

Abstract: The present invention relates to a novel cyclic olefin compound, a polymer including the cyclic olefin compound, a liquid crystal alignment film including the polymer, and a liquid crystal display device including the liquid crystal alignment film. Since the polymer includes the cyclic olefin compound as a main chain, the thermal stability is excellent and the photoreactive speed is high. Accordingly, the production time can be reduced, the production cost can be reduced, and the anchoring force of the liquid crystal can be increased because the alignment property is stabilized due to the curing.

Abstract: The invention relates to a method for producing alkyl polyglycol carboxylic acids and polyglycol dicarboxylic acids by means of direct oxidation.

Abstract: [PROBLEMS] To provide: a norbornene compound addition polymer which has excellent heat resistance and suffers no decrease in the excellent transparency and mechanical properties even when exposed to high temperatures during molding, processing, or use; and a process for producing the polymer. [MEANS FOR SOLVING PROBLEMS] The norbornene compound addition polymer comprises, as an essential ingredient, repeating structural units derived from a substituted norbornene compound monomer, wherein the total content of atoms of the transition metals in Group 10 of the Periodic Table, halogen atoms, phosphorus atoms, aluminum atoms, boron atoms, and sulfur atoms is 50 wt. ppm or lower. The process for producing a norbornene compound addition polymer comprises bringing a norbornene compound addition polymer comprising, as an essential ingredient, repeating structural units derived from a substituted norbornene compound monomer into contact with an ion-exchanging lamellar inorganic compound.

Abstract: A process for the preparation of a catalyst that contains at least one modified zeolite, whereby said zeolite—before being modified—has a maximum pore opening diameter that is less than or equal to 7 ?, and whereby said process comprises at least: a) One stage for introducing at least one metal that is selected from among the metals of groups VIB and VIII of the periodic table on a substrate that is based on at least one protonated zeolite, b) One stage for treating said zeolite in the presence of at least one molecular compound that contains at least one silicon atom, and said compound that has a diameter that is greater than the maximum opening diameter of the pores of said zeolite, c) At least one heat treatment stage, is described.

Abstract: Disclosed herein are various processes, including continuous fluidized-bed gas-phase polymerization processes for making a high strength, high density polyethylene copolymer, comprising (including): contacting monomers that include ethylene and optionally at least one non-ethylene monomer with fluidized catalyst particles in a gas phase in the presence of hydrogen gas at an ethylene partial pressure of 100 psi or more and a polymerization temperature of 120° C. or less to produce a polyethylene copolymer having a density of 0.945 g/cc or more and an ESCR Index of 1.0 or more wherein the catalyst particles are prepared at an activation temperature of 700° C. or less, and include silica, chromium, and titanium.

Abstract: A composition includes a post-cured polymer. A post-cured polymer includes a reaction product of a first cycloolefin and a metathesis catalyst having ruthenium, osmium, or both ruthenium and osmium. The post-cured polymer has a glass transition temperature in a range that is greater than 340 degrees Celsius. An associated article and a method are also provided.

Abstract: Catalyst for the polymerization and/or copolymerization of olefins which has a chromium content of from 0.01 to 5% by weight, based on the element in the finished catalyst, is supported on a finely divided inorganic support and is obtainable by concluding calcination at temperatures of from 350 to 1050° C. and has a zinc content of from 0.01 to 10% by weight, based on the element in the finished catalyst.

Abstract: The present invention provides a liquid addition-curable silicone composition for a fiber-reinforced composite material which, when combined with a reinforcing fiber and molded, yields molded items with excellent heat resistance and strength that can be used favorably for aircraft members (such as the main wings and fuselage of passenger aircraft or military aircraft), spacecraft members, artificial satellite members, electrical and electronic device componentry (such as mobile telephone cases), construction members (such as repairing or reinforcing materials for engineering and construction) and automobile members (such as structural materials surrounding the engine) that are exposed to high temperatures. The invention also provides a fiber-reinforced silicone composite material, and an effective method of producing the composite material.

Abstract: A new P—N—P ligand in which each phosphorus atom is bonded to two ortho-fluorine substituted phenyl groups is useful in ethylene oligomerizations. In combination with i) a source of chromium and ii) an activator such as methalumoxane; the ligand of this invention may be used to prepare an oligomer product that contains a mixture of hexenes and octenes. The hexenes and octenes produced with this ligand contain very low levels of internal olefins when produced under preferred reaction conditions.

Abstract: The invention related to a process for the polymerization of at least one aliphatic C2-20 or aromatic C4-20 hydrocarbyl mono- or multiolefin in the presence of a catalyst and an aluminum comprising co-catalyst, wherein the catalyst comprises a composition of a metal-organic reagent, a spectator ligand and optionally at least one equivalent of a hydrocarbylating agent. The invention further relates to a polymer obtainable by the process of the invention.

Abstract: An extrudate comprising an inorganic oxide and a comb-branched polymer is disclosed. The calcined extrudates are useful catalysts or catalyst supports. A palladium-gold catalyst prepared with a calcined titania extrudate of the invention is useful in making vinyl acetate from ethylene, acetic acid, and oxygen or oxygen-containing gas. A calcined transition metal zeolite extrudate of the invention is used as a catalyst in oxidizing organic compounds with hydrogen peroxide. Incorporation of a comb-branched polymer improves the mechanical properties of inorganic oxide extrudates.

Abstract: The present invention relates to the removal of hydrocarbon residues from a catalyst and more specifically the air activation of a catalyst containing hydrocarbon residues. It also relates to extruded pipe and utility conduit resins comprising polyethylene, household/industrial chemicals container resins, and to a polyethylene resin particularly suitable for large parts by blow molding and sheet extrusion procedures, wherein the resin is made by a process using an activated chromium and titanium-based catalyst.

Abstract: A catalyst for olefin polymerization of the present invention includes a solid titanium catalyst component (I) including titanium, magnesium, halogen, and a cyclic ester compound (a) represented by the following formula (1): wherein n is an integer of 5 to 10; R2 and R3 are each independently COOR1 or R, and at least one of R2 and R3 is COOR1; a single bond (excluding Ca—Ca bonds, and a Ca—Cb bond in the case where R3 is R) in the cyclic backbone may be replaced with a double bond; a plurality of R1's are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms; and a plurality of R's are each independently a hydrogen atom or a substituent, but at least one of R's is not a hydrogen atom, and an organometal compound catalyst component (II). When this catalyst for olefin polymerization is used, an olefin polymer having a broad molecular weight distribution can be produced.

Abstract: The present invention relates to a method for preparing polymers by gas-phase deposition polymerization, initiated by a zero valent metal and an initiator.

Abstract: Radical polymerization process for the preparation of halogenated polymers employing one or more ethylenically unsaturated monomers, at least one of which is chosen from halogenated monomers, molecular iodine and one or more radical-generating agents chosen from diazo compounds, peroxides and dialkyl diphenylalkanes Radical polymerization process for the preparation, starting from the halogenated polymers prepared by the process as described above, of block copolymers, at least one block of which is a halogenated polymer block. Halogenated polymers which have a number-average molecular mass Mn of greater than 1.0×104 and an Mz/Mw ratio of less than 1.65. Block copolymers, at least one block of which is a block of halogenated polymer identical to the halogenated polymers described above. Block copolymers comprising at least one halogenated polymer block which have a number-average molecular mass Mn of greater than 1.5×104 and a polydispersity index Mw/Mn of less than 1.60.

Abstract: Processes for the living polymerization of olefin monomers with terminal carbon-carbon double bonds are disclosed. The processes employ initiators that include a metal atom and a ligand having two group 15 atoms and a group 16 atom or three group 15 atoms. The ligand is bonded to the metal atom through two anionic or covalent bonds and a dative bond. The initiators are particularly stable under reaction conditions in the absence of olefin monomer. The processes provide polymers having low polydispersities, especially block copolymers having low polydispersities. It is an additional advantage of these processes that, during block copolymer synthesis, a relatively small amount of homopolymer is formed.

Abstract: This invention is based upon the discovery that a catalyst system which is comprised of (a) palladium or a palladium compound and (b) a fluorinated alcohol is effective for polymerizing norbornene-functional monomers into polynorbornene-functional polymers. It has been further discovered that this catalyst system is more effective in polymerizing certain norbornene-functional monomers that are difficult to polymerize, such as norbornene ester monomers, than prior art catalyst systems. The activity of the catalyst systems of this invention can be further improved with respect to polymerizing some monomers by including a Lewis acid and/or a ligand, such as a phosphine or a carbene, in the system. In any case, the catalyst systems of this invention offer the advantage of being soluble in a wide variety of solvents, relatively inexpensive, and capable of polymerizing many norbornene-functional monomers that are difficult to polymerize with conventional catalyst systems.

Abstract: There are provided (1) a process for producing a compound, which comprises the step of contacting a compound (A) defined by the formula, M1L13, a compound (B) defined by the formula, R1t-1TH, and a compound (C) defined by the formula, R2t-2TH2; (2) a catalyst component for addition polymerization, which comprises a compound produced by said process; (3) a process for producing a polymerization catalyst, which comprises the step of contacting said catalyst component with a transition metal compound and an optional organoaluminum compound; and (4) a process for producing an addition polymer, which comprises the step of addition polymerizing an addition polymerizable monomer in the presence of a catalyst produced by said process.

Abstract: The instant invention relates to a process for the preparation of hydroxy-vinyl-aromatic polymers in particular 4-hydroxystyrene polymers or copolymers by anionic or controlled radical polymerization of the respective monomer, wherein the hydroxy functionality is blocked with a protective group which is subsequently removed in a hydrogenation process. The resulting (co)polymers have a narrow polydispersity and are useful for manufacturing photoresists.

Abstract: Disclosed is a method for preparing dimethyl dipropargylmalonate polymer containing exclusively six-membered ring structure by using supercritical or sub-critical carbon dioxide as a solvent with a transition metal chloride catalyst.

Abstract: A copolymer of ethylene and a higher alpha olefin, preferably 1-hexene, can be produced using an activated chromium containing catalyst system and a cocatalyst selected from the group consisting of trialkylboron, trialkylsiloxyalutninum, and a combination of trialkylboron and thalkylaluminum compounds. The polymerization process must be carefully controlled to produce a copolymer resin having an exceptionally broad molecular weight distribution, extremely high PENT ESCR values, and a natural branch profile that impacts branching preferably into the high molecular weight portion of the polymer. The resulting copolymer resin is especially useful in high stiffness pipe applications.