POLYMERS OF HIGHER OLEFINS

The synthesis of isotactic polymers of higher a-olefins was discovered in 1955, simultaneously with the synthesis of isotactic PP (1,2) syndiotactic polymers of higher a-olefins were first prepared in 1990 (3,4). The first commercial production of isotactic poly(l-butene) [9003-29-6] (PB) and poly(4-methyl-l-pentene) [9016-80-2] (PMP) started in 1965 (5). 

Higher a-olefins can also be polymerized with cationic initiators to fiquid oligomeric materials with isomerized stmctures. These fiquids are manufactured commercially and used as lubricating oils. 

Manufacture of Monomers. The monomers of the greatest interest are those produced by oligomerization of ethylene (qv) and propylene (qv). Some olefins are also available as by-products from refining of petroleum products or as the products of hydrocarbon (qv) thermal cracking. 

1-Butene. Commercial production of 1-butene, as well as the manufacture of other linear a-olefins with even carbon atom numbers, is based on the ethylene oligomerization reaction. The reaction can be catalyzed by triethyl aluminum at 180—280°C and 15—30 MPa ( 150 300 atm) pressure (6) or by nickel-based catalysts at 80—120°C and 7—15 MPa pressure (7—9). Another commercially developed method includes ethylene dimerization with the Ziegler dimerization catalysts, (OR) —AIR, where R represents small alkyl groups (10). In addition, several processes are used to manufacture 1-butene from mixed butylene streams in refineries (11) (see BuTYLENEs). 

4-Methyl-l-Pen ten e. This olefin is produced commercially by dimeriza tion of propylene in the presence of potassium-based catalysts at 150—160°C and - 10 MPa. Commercial processes utilize several catalysts, such as sodium-promoted potassium carbonate and sodium- and alurninum-promoted potassium hydroxide (12—14) in a fixed-bed reactor. The reaction produces a mixture of C olefins containing 80—85% of 4-methyl- 1-pentene. 

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OLEFIN POLYMERS - POLYMERS OF HIGHER OLEFINS] (Vol 17) [INCLUSIONCOMPOUNDS] (Voll4)... 

Kaminsky catalysts - [OLEFINPOLYMERS - POLYETHYLENE - HIGH DENSITY POLYETHYLENE] (Vol 17) - [OLEFINPOLYMERS - POLYETHYLENE - INTRODUCTION] (Vol 17) -higher a-olefms [OLEFIN POLYMERS - POLYMERS OF HIGHER OLEFINS] (Vol 17) -for LLDPE production [OLEFIN POLYMERS - POLYETHYLENE - LINEAR LOW DENSITY POLYETHYLENE] (Vol 17)... 

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