ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Isobutylene tetramers (IB4) were obtained in high yield by the cationic dimerization of commercial diisobutylene (DIB) (2,4,4-trimethyl-1-pentene with isomeric impurities) with CF3SO3O3H or CH3COClO4 as catalyst. The best IB4 yields (80-90%) were achieved at 0-30°C in nonpolar solvents (n-hexane and CCl4). The major components in the IB4 produced under these conditions were 2,2,6,6,8,8-hexamethyl-4-methylenenonane (8) and 2,2,4,6,6,8,8-heptamethyl-4-nonene (9) that arose via simple linear dimerization of DIB. The yield of IB4 was almost independent of the monomer concentration ranging from 10 to 50 vol % at 0°C, but decreased at higher temperatures (〉50°C) or in a polar solvent [(CH2Cl)2] because of the formation of higher oligomers and side reactions such as cracking. A Lewis acid catalyst (AlEtCl2) resulted in a very complex mixture of C12-C20 hydrocarbons at 0°C in CCl4; the yield of IB4 was less than 40%. The catalytic difference between oxo acids and metal halides is discussed.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1982.070270119
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