DIMERIZATION OF ISOAMYLENE - ION-EXCHANGE RESIN AND ACID-TREATED CLAY AS CATALYSTS

Dimerization of isoamylene (2-methyl-2-butene and 2-methyl-1-butene) was carried out in the presence of a cation exchange resin (Amberlyst-15) and acid-treated clay (Engelhard, F-24) as catalysts in the temperature range of 333-373 K. The product mixture was analyzed by GLC and GLC-MS, and different isomers of diisoamylene were identified. Kinetic analysis of the experimental data showed that the dimerization of isoamylene followed first-order kinetics in the concentration and temperature range studied. The first-order behaviour has been explained on the basis of a Rideal-Eley mechanism. The rate of reaction with the clay catalyst was found to be lower as compared to that with the cation exchange resin but the selectivity for the individual dimers was unaffected.