摘要:
Supported catalyst systems, methods of forming polyolefins and the formed polymers are generally described herein. The methods generally include identifying desired polymer properties, providing a transition metal compound and selecting a support material capable of producing the desired polymer properties, wherein the support material includes a bonding sequence selected from Si-O-Al-F, F-Si-O-Al, F- Si-O-Al-F and combinations thereof.
摘要:
Catalyst systems, polymers and methods of forming the same are described herein. The catalyst systems generally include an inorganic support material having a bonding sequence selected from Si-O-Al-F, F-Si-O-Al, F-Si-O-Al-F and combinations thereof, wherein the inorganic support material has an acid strength (pKa) of less than about 4.8 and a transition metal compound, wherein the transition metal compound is represented by the formula [L]mM[A]n; wherein L is a bulky ligand, A is a leaving group, M is a transition metal and m and n are such that a total ligand valency corresponds to a transition metal valency.
摘要:
Supported catalyst systems and methods of forming the same are described herein. The methods generally include providing an inorganic support material and contacting the inorganic support material with an aluminum fluoride represented by the formula A1FpX3-pBq to form an aluminum impregnated support, wherein X is selected from Cl, Br and OH-, B is H2O, p is selected from 1 to 3 and q is selected from 0 to 6. The method further includes contacting the aluminum impregnated support with a transition metal compound to form a supported catalyst system, wherein the transition metal compound is represented by the formula [L]mM[A]n; wherein L is a bulky ligand, A is a leaving group, M is a transition metal and m and n are such that a total ligand valency corresponds to the transition metal valency.
摘要:
Supported catalyst systems, methods of forming the supported catalyst systems and polymerization processes including the supported catalyst systems are described herein. The methods generally include providing an inorganic support composition, wherein the inorganic support composition comprises aluminum, fluorine and silica and contacting the inorganic support composition with a transition metal compound to form a supported catalyst system, wherein the transition metal compound is represented by the formula [L]mM[A]n; wherein L is a bulky ligand, A is a leaving group, M is a transition metal and m and n are such that a total ligand valency corresponds to the transition metal valency. The methods further include contacting the inorganic support composition, the transition metal compound, the supported catalyst system or combinations thereof with at least one compound represented by the formula XRn, wherein X is selected from Group 12 to 13 metals, lanthanide series metals or combinations thereof and each R is independently selected from alkyls, alkoxys, aryls, aryloxys, halogens, hydrides, Group 1 or 2 metals, organic nitrogen compounds, organic phosphorous compounds and combinations thereof and n is from 2 to 5.
摘要:
Ethylene polymerization processes employing bis-imino pyridinyl transition metal components which exhibit C2, C2v or Cs symmetry. Catalyst components of the same or different symmetries may be employed to control polymerization characteristics and characteristics of the resulting polymer products such as polymer yield and polymer molecular weight. The transition metal catalyst component is characterized by the formula: (I) wherein M is a Group 4-11 transition metal, n is an integer within the range of 1-3, Q is a halogen or a C1 - C2 alkyl group, and PY is a pyridinyl group which is coordinated with M through the nitrogen atom of the pyridinyl group. Further, with respect to formula (I), A is a methyl group, a phenyl group, or a substituted phenyl group and B1 and B2 are the same or different aromatic groups depending on the symmetry of the catalyst component. The catalyst component and an activating co-catalyst component are contacted with ethylene in a polymerization reaction zone which is free of hydrogen or contains hydrogen in an amount which is less than 5 mole % of the ethylene under polymerization conditions to produce a polymer product which can be a ethylene homopolymer or a copolymer of ethylene and C3+ alpha olefin, specifically an ethylene-propylene copolymer.
摘要:
A syndiotactic polypropylene comprising a melting temperature of greater than 160° C., a percentage of syndiotactic pentads greater than 95%, a toluene soluble fraction of equal to or less than 0.4, and a molecular weight of from 10,000 Daltons to 1,000,000 Daltons. A syndiotactic polypropylene comprising a melting temperature of greater than 170° C., a molecular weight of from 100,000 Daltons to 300,000 Daltons, a molecular weight distribution of less than 3, and a toluene soluble fraction of less than 0.4. A syndiotactic polypropylene comprising a tensile modulus of equal to or greater than 60,000 psi, a tensile strength at yield of equal to or greater than 3,600 psi, a tensile strength at break of equal to or greater than 3,900 psi, an elongation at yield of equal to or greater than 13%, and an elongation at break of equal to or greater than 400%.
摘要:
A method of producing a polymer comprising contacting in a reaction zone under conditions suitable for polymerization of an alpha-olefin monomer with a metallocene catalyst having at least three asymmetric centers, and recovering an alpha-olefm polymer from the reaction zone. A method of polymerizing propylene comprising contacting in a reaction zone propylene, a cocatalyst, and a metallocene catalyst having the formula including stereoisomers: and recovering polypropylene from the reaction zone. A polypropylene composition having a tensile modulus from 40,000 psi to 300,000 psi, a tensile strength at yield from 2,000 psi to 6,000 psi, a tensile strength at break from 1,000 psi to 3,500 psi, a tensile strength from 1,000 psi to 5,000 Kpsi, an elongation at yield of greater than or equal to 10%, and an elongation at break from 50% to 500%.
摘要:
Olefin polymerization processes are described herein. In one embodiment, the process generally includes introducing propylene monomer to a reaction zone, disposing an isospecific metallocene catalyst within the reaction zone, wherein the isospecific metallocene catalyst has the formula: (SiRA2)(CpRB4)(FluRC8)MAn ; wherein Si is silicon and is a structural bridge between Cp and Flu, Cp is a cyclopentadienyl group, Flu is a fluorenyl group, M is a transition metal, A is a leaving group, n is an integer equal to the valence of M minus 2, RA is independently selected from hydrogen, alkyls, aromatics and combinations thereof, RB is independently selected from hydrogen, alkyls and combinations thereof and RC is independently selected from hydrogen, alkyls, aromatics and combinations thereof, contacting the propylene monomer with the isospecific metallocene catalyst to form isotactic polypropylene and recovering the isotactic polypropylene from the reaction zone.
摘要:
Catalyst compositions and processes for the polymerization of ethylenically unsaturated monomers to produce polymers, including copolymers or homopolymers. Such monomers include ethylene, C3+ alpha olefins and substituted vinyl compounds, such as styrene and vinyl chloride. The polymerization catalyst characterized by the formula B(FIuL)MQn in which Flu is a fluorenyl group substituted at at least the 2,7- and 3,6-positions by hydrocarbyl groups, preferably relatively bulky hydrocarbyl groups. L is a substituted or unsubstituted cyclopentadienyl, indenyl or fluorenyl group or a heteroorgano group, XR, in which X is a heteroatom from Group 15 or 16 of the Periodic Table of Elements, such as nitrogen, R is an alkyl group, a cycloalkyl group or an aryl group and B is a structural bridge extending between the groups L and Flu, which imparts stereorigidity to the ligand structure, M is a Group 4 or Group 5 transition metal, such as titanium, zirconium or hafnium and Q is selected from the group consisting of chlorine, bromine, iodine, an alkyl group, an amino group, an aromatic group and mixtures thereof, with n being 1or 2.