A KINETIC STUDY OF THE METATHETICAL AND ADDITION REACTIONS CHARACTERISTIC OF ALLYL POLYMERIZATION

Abstract

The rate constants of the reactions[Formula: see text]have been measured in the gas phase between 50° and 142 °C:[Formula: see text]where ki is the (known) rate constant for the reaction[Formula: see text]The significance of these values is discussed in relation to the propagation and chain transfer processes in the polymerization of allyl alcohol. A consideration of the rates of addition of free radicals to a series of monomers of diverse reactivity reveals that a correlation exists between the rate constants for the addition of the ethyl radical in the gas phase and of certain polymer radicals in the liquid phase.An application of the general equation proposed by Bamford, Jenkins, and Johnston for radical reactivity leads to the conclusion that kp ≈ 2k7 and that kP/kf ≈ k7/k6 = 1.8 for allyl alcohol at 60 °C. Predictions based upon these relationships are compared with experimental data for the propagation and degree of homopolymerization of allyl alcohol and for inhibition and propagation in copolymerization; reasonable agreement is found in all cases.