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Olefin Copolymerization (olefin + copolymerization)
Selected AbstractsEthylene/,-olefin copolymerization using diphenylcyclopentadienyl-phenoxytitanium dichloride/Al(iBu)3/[Ph3C][B(C6F5)4] catalyst systemsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Hongchun Li Abstract Copolymerization of ethylene with 1-octene and 1-octadecene using constrained geometry catalysts 2-(3,4-diphenylcyclopentadienyl)-4,6-di- tert -butylphenoxytitanium dichloride (1), 2-(3,4-diphenylcyclopentadienyl)-6- tert -butylphenoxytitanium dichloride (2), 2-(3,4-diphenylcyclopentadienyl)-6-methylphenoxytitanium dichloride (3), and 2-(3,4-diphenylcyclopentadienyl)-6-phenylphenoxytitanium dichloride (4) was studied in the presence of Al(iBu)3 and [Ph3C][B(C6F5)4](TIBA/B). The effect of the catalyst structure, comonomer, and reaction conditions on the catalytic activity, comonomer incorporation, and molecular weight of the produced copolymers was also examined. The 1/TIBA/B catalyst system exhibits high catalytic activity and produces high molecular weight copolymers. The melting temperature and the degree of crystallinity of the copolymers show a decrease with the increase in the comonomer incorporation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Ethylene/,-olefin copolymerization with bis(,-enaminoketonato) titanium complexes activated with modified methylaluminoxaneJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 24 2005Li-Ming Tang Abstract Copolymerizations of ethylene with ,-olefins (i.e., 1-hexene, 1-octene, allylbenzene, and 4-phenyl-1-butene) using the bis(,-enaminoketonato) titanium complexes [(Ph)NC(R2)CHC(R1)O]2TiCl2 (1a: R1 = CF3, R2 = CH3; 1b: R1 = Ph, R2 = CF3; and 1c: R1 = t -Bu, R2 = CF3), activated with modified methylaluminoxane as a cocatalyst, have been investigated. The catalyst activity, comonomer incorporation, and molecular weight, and molecular weight distribution of the polymers produced can be controlled over a wide range by the variation of the catalyst structure, ,-olefin, and reaction parameters such as the comonomer feed concentration. The substituents R1 and R2 of the ligands affect considerably both the catalyst activity and comonomer incorporation. Precatalyst 1a exhibits high catalytic activity and produces high-molecular-weight copolymers with high ,-olefin insertion. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6323,6330, 2005 [source] Facile synthetic route to polymerizable hindered amine light stabilizers for transition-metal-catalyzed olefin copolymerizationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 6 2004M. Auer Abstract This work describes a facile method by which a polymerizable hindered amine light stabilizer, 4-(10-undecylidene)-2,2,6,6-tetramethylpiperidine, was prepared in a single-step procedure by means of a Wittig reaction. The monomer was successfully copolymerized with ethylene with a rac -[dimethylsilylenebis(4,5,6,7-tetrahydro-1-indenyl)]zirconium dichloride/methylalumoxane catalyst system. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1350,1355, 2004 [source] FTIR, 13C NMR, and GPC analysis of high-propylene content co- and terpolymers with ethylene and higher ,-olefins synthesized with EtInd2ZrCl2/MAOJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 12 2001M. L. Ferreira Abstract This article reports the results of propylene/,-olefin copolymerization and propylene/ethylene/,-olefin terpolymerization using low concentrations (less than 5 mol %) of long ,-olefins such as 1-octene, 1-decene, and 1-dodecene. Kinetics data are presented and discussed. The highest activity was found with the longest ,-olefin studied (1-dodecene). A possible explanation is proposed for this and other characteristics of the polymers obtained. The effect of low-ethylene contents (4 mol % in the gas phase) on the copolymerization of propylene/,-olefins was also examined. The polymers synthesized were characterized by 13C NMR, gel permeation chromatography, DSC, Fourier transform infrared spectroscopy, and wide-angle X-ray scattering. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2005,2018, 2001 [source] On-line monitoring and fingerprint technology: new tools for the development of new catalysts and polyolefin materialsMACROMOLECULAR SYMPOSIA, Issue 1 2004Arno Tuchbreiter Abstract The High-Output Polymer Screening (HOPS) combines process-relevant automated reactor systems and rapid polymer characterization with on-line polymerization monitoring and automated data acquisition ("electronic notebook") in order to make effective use of advanced data mining tools. This has led to the development of fingerprint technology based upon correlations between spectroscopic data and polymerization process conditions, catalyst compositions, as well as polymer end-use properties. Infrared spectroscopic fingerprints proved to be very useful for accelerating polymer analyses including characterization of polymer molecular architectures as well as non-destructive testing of the mechanical, thermal and other end-use polymer properties. Such spectroscopic fingerprints represent important components of effective on-line quality control systems. With ATR-FT-IR probes on-line monitoring of catalytic olefin copolymerization was performed in solution to measure in real time copolymerization kinetics, catalyst productivities, catalyst deactivation as well as copolymerization parameters and copolymer sequence distributions. Monomer consumption and comonomer incorporation were monitored simultaneously. Advanced fingerprint technology can reduce significantly the need for time- and money consuming polymer testing and can also stimulate the search for new catalyst systems and polymeric materials. [source] | ||||||||||