Ethylene oligomerization

Cryogenic recovery before oligomerization Ethylene Propylene 95% 100%... 

Other high molecular weight hydrocarbon polymers are not biodegradable, but oligomers of <7j -l,4-isoprene (83), butadiene (84), and styrene (85), are degradable. And there has been further confirmation of biodegradation of oligomeric ethylene (86). 

Recent efforts have also been successful in both the polymerization of ethylene oxide and tetrahydrofuran. Both Saegusa et al., and Robinson and Pruckmayr were successful in oligomerizing ethylene oxide under varying conditions. Of somewhat greater... 

Boratabenzene complexes of Group 3 and Group 6 metals serve as effective catalysts for the oligomerization/polymerization of ethylene. For example, [(C5H5B-Ph)2ScPh]2, pretreated with H2, oligomerizes ethylene to furnish 1-alkenes.17a In the case of a Cr(III)-boratabenzene complex, ethylene is polymerized to afford... 

Catalysts based on nickel that dimerize or oligomerize a-olefins have been known for many years and are commercially valuable. The Shell higher olefin process (SHOP), for example, uses Ni(II) catalysts developed by Keim and coworkers such as 1.1 and 1.2 bearing P-O chelating ligands to oligomerize ethylene into higher olefins in the manufacture of surfactants, lubricants, and fine chemicals (Fig. 1) [9-11]. Late transition metals are more suited for the polymerization of... 

SHOP [Shell Higher Olefins Process] A process for producing a-olefins by oligomerizing ethylene, using a proprietary rhodium/phosphine catalyst. The a-olefins can then be iso-merized to internal olefins as required. Invented by W. Keim in the Institut fur Technische Chemie und Petrolchemie, Aachen, in the 1970s. The first plant was built in Geismar, LA, in 1979 the second in Stanlow, Cheshire, in 1982. Licensed worldwide by a consortium of Union Carbide, Davy-McKee, and Johnson Matthey. 

Figure 5. CP/MAS C-NMR spectrum of oligomerized ethylene on H-ZSM-5 zeolite at 295 K. (Reproduced with permission from Ref. 10. Copyright, 1981, Butterworth and Co.)...

These requirements have met using a mixed catalystic system consisting of an iron catalyst complex that can oligomerize ethylene and a zirconium transition metal complex that can copolymerize ethylene and the nonconjugated monomer 5-ethylidene-2-norbomene. Using this catalytic pair nonbrancy poly(ethylene-co5-ethylidene-2-norbomene) and poly (ethylene-col,4-hexadiene) were prepared. 

Research Focus Method for oligomerizing ethylene using alkylaluminum and trialkylaluminum as activators. 

TABLE 1. Reaction Scoping for Oligomerizing Ethylene Using Different Activators... 

The influence of solvent was especially shown by using nickel-containing catalysts based on nickelphosphine complexes. These compounds dissolved in toluene without cocatalysts, oligomerize ethylene to linear a-olefins. Using a suspension in H-hexane, high-molecular-weight linear polyethylene is formed (183). 

Hydrophilic surface active agents containing C1-C4 phosphoric acid derivatives provide limited benefits because of their short aliphatic chain. To address this concern, hydrophilic phosphonic acid derivative containing an oligomeric ethylene glycol component has been prepared. 

A similar catalytic process (Dimersol, Institut Frangais du Petrole), based on a nickel hydride formed in situ from a nickel complex and an aluminium alkyl, has been applied industrially to oligomerize ethylene, propylene, butenes or mixtures of the three. 

HF-SbFs is also an efficient cationic polymerization catalyst [2]. HF-SbFs and other acids such as HF-BF3 readily oligomerize ethylene oxide to mixtures of cyclic ethers [108] which can be subsequently separated (Eq. 48). The key to cyclic ether formation is the presence of anhydrous HF in the conjugate acid systems chain polymers would otherwise be obtained. 

Complexes 3-7 oligomerize ethylene in toluene at 80 °C and 5 MPa to 99 % linear olefins with 98 % a-olefins. Complex 4 reaches an activity of 6000 mol ethylene per mol of catalyst [43]. Applying the reaction in suspension in n-hex-ane, high-molecular-weight linear polyethylene is obtained. 

Some neutral and cationic palladium(II) (RR C(pz)2) complexes have been reported by Tsuji and co-workers.201 The cation [(Me2C(pz)2)Pd(CH2=CH2)]+ undergoes ethylene insertion at —10 °C and oligomerizes ethylene (1 atm) to predominantly linear internal C8 to C24 olefins (ca. 0.1 branches per 2 carbons) at 23 °C. 

The amino-pyrrolate complex 99 is another case of a complex with coordination 4 and two coordinating N atoms. In the temperature range 0-50 °C, the 99/MAO catalyst oligomerizes ethylene (/t/w < 8000, Mw//l/n < 2.8) with high activity (< 8x 102gpK(mmol M)-Ih bar ), whereas the monoligated imino-pyrrolate complex 100 shows moderate polymerization activity (19g (mmol M)-1 h 1 bar-1).1086... 

Figure 2. 1H-NMR spectrum of a living oligomeric ethylene oxide prepared with TPPAICI. (Reproduced from Ref. 6. Copyright 1981 American Chemical Society.)...

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