Kinetics and Mechanism on a Reaction of Allyl Radical with Ethylene

Abstract

To realize the reaction of allyl radical with ethylene, 1, 5-hexadiene was pyrolyzed in excess ethylene by use of a flow type apparatus at 580∼700°C under atmospheric pressure. First-order reaction kinetics fitted the rate of 1, 5-hexadiene decomposition and the rate constant obtained was k=1012.9 exp (-55, 000/RT) sec-1, which indicated that allyl radical generated was effectively quenched by ethylene. The main primary products were cyclopentene (38.0mol%), 1-pentene (28.5), 1-butene+butadiene (19.0) and propylene (14.5). Minor ones were 1, 4-pentadiene and cyclopentadiene. A mechanism was proposed focussing the discussion on C5 products formation from allyl radical and ethylene.