EEthylene polymerization catalysts became available in an enormous variety. The challenge in this research is to find catalysts that are able to connect ethylene molecules in such a way that not only linear chains are produced but variations like branched materials that possess very interesting mechanical properties like linear low density polyethylene (LLDPE). In this contribution, three different types of catalysts are presented that are able to do not only one job at a time but three. These are “intelligent catalysts”. Catalysts of type 1 are homogeneous metallocene complexes that can be activated with methylaluminoxane (MAO).With ethylene they produce their own support and they become heterogeneous catalysts (self-immobilization) and they prevent fouling in polymerization reactors. The produced resin has evenly distributed ethyl branches (without a comonomer) with unique properties and the MAO that is necessary in the activation step can be recycled. Catalysts of type 2 are dinuclear complexes with two different active sites. One centre can oligomerize ethylene and the other one can copolymerize the in statu nascendi produced oligomers with ethylene to give branched LLDPE (a molecule as the smallest reactor for LLDPE) and/or bimodal resins. Catalysts of type 3 are MAO activated iron di (imino) pyridine complexes that are able to oligomerize ethylene to give not only oligomers with even numbered carbon atoms but also odd numbered ones. In this reaction, one catalyst does three jobs at a time: oligomerization, isomerization and metathesis of ethylene.
Severn JR, Chadwick JC, Duchateau R, Friederichs N (2005) bound but not gagged immobilizing single-site α-olefin polymerization catalysts. Chem Rev 105: 4073-147
Kaminsky W (2008) Google archiv. Aktuelle wochenschau.de 48. Woche
Alt HG, Köppl A (2000) Effect of the nature of metallocene complexes of group IV metals on their performance in catalytic ethylene and propylene polymerization. Chem Rev 100:1205- 1222
Sinn H, Kaminsky W, Vollmer HJ (1980) Lebende Polymere bei Ziegler Katalysatoren extremer Produktivität. Angew Chem 92: 396- 402
Sinn H, Kaminsky W (1980) Ziegler-Natta catalysis. Adv Organomet Chem 18: 99-149
Alt HG, Milius W, Palackal SJ (1994) Verbrückte Bis(fluorenyl)komplexe des Zirconiums und Hafniums als hochreaktive Katalysatoren bei der homogenen Olefinpolymerisation. Die Molekülstrukturen von (C13H9-C2H4-C13H9) und (η5:η5-C13H8-C2H4 -C13H8)ZrCl2. J Organomet Chem 472:113-118
Alt HG, Samuel E (1998) Fluorenyl complexes of zirconium and hafnium as catalysts for olefin polymerization. Chem Soc Rev 27: 323-329
Peifer B, Milius W, Alt HG (1998) Verbrückte indenyliden–cyclopentadienylidenkomplexe des typs (C9H5CH2Ph–X–C5H4)MCl2 (X=CMe2, SiMe2; M=Zr, Hf) als Metallocenkatalysatoren für die Ethylenpolymerisation. Die Molekülstrukturen von (C9H5CH2Ph–CMe2–C5H4)MCl2 (M=Zr, Hf). J Organomet Chem 558: 111-121
Alt HG, Jung M (1999) C2-bridged metallocene dichloride complexes of the types (C13H8–CH2CHR– C9H6−nR′n)ZrCl2 and (C13H8–CH2CHR–C13H8) MCl2 (n=0, 1; R=H, alkenyl; R′=alkenyl, benzyl; M=Zr, Hf) as self-immobilizing catalyst precursors for ethylene polymerization. J Organomet Chem 580: 1-16
Alt HG (1999) The heterogenization of homogeneous metallocene catalysts for olefin polymerization. J. Chem. Soc., Dalton Trans: 1703-1710
Alt HG (2005) Self-immobilizing catalysts and cocatalysts for olefin polymerization. Dalton Trans: 3271-3276
Licht A, Alt HG (2002) Synthesis of novel metallacyclic zirconocene complexes from ω-alkenyl-functionalized zirconocene dichloride complexes and their use in the α-olefin polymerization. J Organomet Chem 648: 134-148
Alt HG (2006) Metallacyclic metallocene complexes as catalysts for olefin polymerization. Coord Chem Rev 250: 2-17
Görl C, Alt HG (2007) Iron complexes with ω-alkenyl substituted bis(arylimino) pyridine ligands as catalyst precursors for the oligomerization and polymerization of ethylene. J Mol Cat A Chem 273: 118-132
Görl C, Alt HG (2007) The combination of mononuclear metallocene and phenoxyimine complexes to give trinuclear catalysts for the polymerization of ethylene. J Organomet Chem 692: 5727-5753
Görl C, Alt HG (2007) Influence of the para-substitution in bis(arylimino)pyridine iron complexes on the catalytic oligomerization and polymerization of ethylene. J Organomet Chem 692:4580-45925
Kestel-Jakob A, Alt HG (2007) Boryl-substituted zirconocene dichloride complexes as catalyst precursors for homogeneous ethylene polymerization. Z Naturforsch 62b: 314-322
Ostoja Starzewski KHA, Kelly WM, Stumpf A, Freitag D (1999) Donor/acceptor metallocenes: A new structure principle in catalyst design. Angew. Chem Int Ed 38: 2439-2443
Ostoja Starzewski KHA (2004) D/A-metallocenes: The new dimension in catalyst design. Macromol Symp 213: 47-56
Schilling M, Bal R, Görl C, Alt HG (2007) Heterogeneous catalyst mixtures for the polymerization of ethylene. Polymer 48: 7461- 7475
Böhmer I, Alt HG (2009) Influence of triphenylphosphine on the activity of heterogeneous iridium, rhodium and platinum containing catalysts for the dehydrogenation of saturated hydrocarbons. J Organomet Chem 694:1001-1010
Taubmann S, Alt HG (2008) Catalytic dehydrogenation of cyclooctane in homogeneous solution with titanium, zirconium and hafnium complexes containing N,O-chelating ligands. J Mol Cat A Chem 289: 49-56
Alt HG, Denner CE, Taubmann S (2009) "Like Phoenix from the ashes"! Thermally decomposed metallocene complexes as catalysts for CH activation reactions. JJC 4: 45-54
Alt, H. G. (2015). Intelligent catalysts for ethylene oligomerization and polymerization. Polyolefins Journal, 2(1), 17-25. doi: 10.22063/poj.2015.1103
MLA
Helmut G. Alt. "Intelligent catalysts for ethylene oligomerization and polymerization". Polyolefins Journal, 2, 1, 2015, 17-25. doi: 10.22063/poj.2015.1103
HARVARD
Alt, H. G. (2015). 'Intelligent catalysts for ethylene oligomerization and polymerization', Polyolefins Journal, 2(1), pp. 17-25. doi: 10.22063/poj.2015.1103
VANCOUVER
Alt, H. G. Intelligent catalysts for ethylene oligomerization and polymerization. Polyolefins Journal, 2015; 2(1): 17-25. doi: 10.22063/poj.2015.1103