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  • 1
    Electronic Resource
    Electronic Resource
    Supported vanadium catalyst for isospecific propylene polymerization (1989)
    s.l. : American Chemical Society
    Macromolecules 22 (1989), S. 4134-4136 
    Details
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ma00200a060
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  • 2
    Electronic Resource
    Electronic Resource
    Facilitated oxygen transport in an ionomer membrane containing cobaltous ions (1995)
    Weinheim : Wiley-Blackwell
    Macromolecular Rapid Communications 16 (1995), S. 927-933 
    Details
    ISSN: 1022-1336
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A new oxygen/nitrogen separation membrane based on an ionomer of sulfonated EPDM (ethylene-propene-diene terpolymer) containing Co2+ ions was synthesized and investigated. It was found that the oxygen permeability coefficient and the separation factor for O2/N2 of the ionomer membrane are simultaneously enhanced at lower gas pressure difference. This result is believed to be caused by a polymer coordinate complex formed in the ionomer. ESR spectra provided an evidence of the cobalt-oxygen adduct.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/marc.1995.030161208
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  • 3
    Electronic Resource
    Electronic Resource
    Syndiotactic polymerization of styrene with cyclopentadienyltribenzyloxytitanium/methylaluminoxane catalyst (1997)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 198 (1997), S. 1823-1828 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Syndiotactic polystyrene was efficiently prepared in the presence of a homogeneous catalyst composed of (η5-cyclopentadienyl)tribenzyloxytitanium and methylaluminoxane (MAO) as a cocatalyst. Influences of various polymerization conditions, e.g., [Ti]. [MAO], [St], temperature and the content of retained trimethylaluminium (TMA) in MAO on the catalytic activity, syndiotacticity and molecular weight of the polymer were studied. It was found that the retained TMA plays an important role in the polymerization. Lowering the retained TMA content in MAO decreases the activity of the catalyst remarkably. Addition of external alkylaluminium (TMA or triisobutylaluminium) into the catalyst system with MAO containing low amounts of retained TMA promotes styrene polymerization.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1997.021980611
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  • 4
    Electronic Resource
    Electronic Resource
    Homo- and copolymerization of ethylene with prepolymerized Ti-Mg supported catalyst (1992)
    Basel : Wiley-Blackwell
    Die Makromolekulare Chemie, Rapid Communications 13 (1992), S. 357-361 
    Details
    ISSN: 0173-2803
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/marc.1992.030130704
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  • 5
    Electronic Resource
    Electronic Resource
    Effect of ethyl benzoate on the microstructure distributions of olefin homopolymers and copolymers prepared with supported titanium catalyst (1990)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 191 (1990), S. 89-97 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The microstructure distributions of ethylene-propene(EP) copolymers and propene homopolymers prepared with supported titanium catalyst were analyzed by 13C NMR spectroscopy. A two-site model with an isospecific site and a non-stereospecific site was used to describe the stereospecific polymerization of propene. A second two-site model with individual r1r2 = 1 was applied to the analysis of the ethylene-propene copolymerization. The addition of an external base, ethyl benzoate (EB), alters the relative concentrations of catalytic sites. Based on the comparison of the results from the homopolymers and copolymers prepared under different EB concentrations, the correlations between the stereospecificity and the activity toward the monomers were established: the isospecific site produces the copolymer with lower ethylene content; the non-stereospecific site gives the copolymer with higher ethylene content.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1990.021910107
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  • 6
    Electronic Resource
    Electronic Resource
    Stereospecific polymerization of butene-1 with supported titanium catalyst (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 2287-2293 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Butene-1 was polymerized with a highly-active supported titanium catalyst which was developed in this laboratory. The influences of various conditions (e.g., catalyst composition, temperature, external ester, H2, triethylaluminum, and catalyst concentration) on the catalytic activity, decay of polymerization rate, molecular weight, and isotacticity of the products were studied in detail. The structural properties of the PB-1 were characterized by WAXD, DSC, and 13C-NMR. It was found that the catalyst TiCl4, Ti(OBu)4/MgCl2/ethyl benzoate (EB)/Ph2SiCl2-AlEt3 shows high activity, i.e., 3.2 × 104 g PB/g Ti h. Isotacticity of the product was increased by adding p-CH3C6H4COOEt into the catalytic system. Molecular weight of the product can be easily controlled by H2. The decay of polymerization rate with time fulfills the equation: Rt - Rs = (Ro - Rs)e-βt. © 1993 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080310911
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  • 7
    Electronic Resource
    Electronic Resource
    Atactic polymerization of propylene catalyzed by mono(η5-cyclopentadienyl)titanium tribenzyloxide combined with methylaluminoxane (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 36 (1998), S. 2051-2057 
    Details
    ISSN: 0887-624X
    Keywords: propylene polymerization ; metallocene catalyst ; methylaluminoxane ; atactic polypropylene ; regioselectivity ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Propylene has been polymerized with mono(η5-cyclopentadienyl)titanium tribenzyloxide activated with methylaluminoxane (MAO). It was found that the content of residual trimethylaluminium (TMA) in MAO has a determinative effect on the polymerization. An excess of TMA in the catalyst system reduces the Ti species to inactive lower valent states. The catalyst system gives medium molecular-weight atactic polypropylene (Mv = 2-7 × 104) with narrow molecular weight distribution (Mw/Mn = 1.4-1.8). The polymer has a stereoirregular structure described by Bernoullian statistics. Statistical analysis of the regiotriad distribution of the polypropylene chains indicates a regioblock microstructure. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2051-2057, 1998
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Terpolymerization of ethylene, propylene, and butene-1 with highly active supported titanium catalyst (1990)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 28 (1990), S. 1237-1254 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An investigation of ethylene-propylene-butene-1 terpolymerization in the presence of TiCl4, Ti(OBu)4/MgCl2/ethylbenzoate (EB)/π2SiCl2/AlEt3 catalyst is described. The catalytic efficiency is very high, i.e., 86000g/g Ti under ambient conditions. The decay rate of terpolymerization with time fulfills the equation: Rt = Rs + (R0 - Rs)e-βt. Characterizations with DSC, WAXD, 13C-NMR, and solvent extraction of the resulting terpolymers were studied. Terpolymers of certain composition are elastomers without detectable crystallinity, which demonstrates a rather random sequence distribution and makes them promising for quality rubber. The assignment of the chemical shifts in 13C-NMR spectra is made. The gas permeabilities of the terpolymer membrane is of PO2 = 2.35 × 10-9 cm3 (STP) cm/cm2 s cm Hg and PO2/PN2 = 3.8 under optimum conditions.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1990.080280523
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  • 9
    Electronic Resource
    Electronic Resource
    Magnesium chloride supported high mileage catalysts for olefin polymerization. XXI. Isospecific and regiospecific vanadium catalyst for propylene polymerization (1990)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 28 (1990), S. 2609-2632 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several CW-V catalysts were prepared by supporting VCl4 on Mg Cl2 with ethyl benzoate and CH-V catalysts prepared by reacting MgCl2.ROH, phthalic anhydride, and VCl4. These vanadium catalysts, activated with TEA (triethyl aluminum)/MPT (methyl-p-toluate) produce mainly (88-96%) refluxing n-heptane insoluble isotactic PP. The active site has \documentclass{article}\pagestyle{empty}\begin{document}$ k_{p,i} = 1580 \left( M {\rm s} \right)^{ - 1}, k_{tr,i}^{\rm A} = 2 \times 10^{ - 3} {\rm s}^{ - 1} , k_{tr}^{\rm H} = 3.8 \times 10^{ - 2} \left( {\rm torr} \right)^{ - {1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}} {\rm s}^{ - 1}$\end{document} for the isospecific ones and \documentclass{article}\pagestyle{empty}\begin{document}$ k_{p,a} = 58 \left( M {\rm s} \right)^{ - 1} ,k_{tr,a}^{\rm A} = 3 \times 10^{ - 3} {\rm s}^{ -1}$\end{document} for the nonspecific sites. Catalyst of VCl3 supported on MgCl2 has comparable productivity as the VCl4/MgCl2 catalyst but catalyst of VCl2 supported on MgCl2 exhibit only one-ninth of the productivity. Extensive comparison has been made between the CW-V and the CW-Ti systems which revealed striking similarities between their polymerization behaviors. MgCl2 exerts profound influence on the stereochemical control of the vanadium ion on its activity for monomer coordination and insertion.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1990.080281003
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  • 10
    Electronic Resource
    Electronic Resource
    Synthesis of the block copolymer of styrene and 1-butene with a novel supported Ti-catalyst (1996)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 34 (1996), S. 2909-2914 
    Details
    ISSN: 0887-624X
    Keywords: Ziegler-Natta catalyst ; coordination copolymerization ; styrene-1-butene block copolymer ; block copolymer ; polymer fractionation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The present investigation deals with sequential block copolymerization of styrene and 1-butene with a novel MgCl2-supported TiCl4 catalyst modified with a rare earth compound NdClx(OR)y (SN-1 catalyst), which was developed in our laboratory. The catalytic activities are 1300-2500 g/g·Ti·h. Analyses of copolymers with solvent extraction, 13C-NMR, WAXD, GPC, and DSC was performed. The results indicate that the SN-1 catalyst selectively gave crystalline diblock copolymers of isotactic polystyrene and isotactic poly(1-butene), with the styrene unit content of 30-60 mol %. © 1996 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
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