Kinetic Constants of Isoprene Polymerization on a Multicenter Gadolinium Catalyst

Abstract

In the description of multicenter ion-coordination polymerization of isoprene on the catalytic system GdCl₃· n(i-C₃Н₇OH)‒Al(i-C₄H₉)₃ the inverse kinetic task for the scheme of a process with slow initiation has been solved. The task of determining the number of active centers of polymerization was solved by deconvolution of experimental MWDs through superposition of Flory distributions. It has been shown that four types of active centers participate in polymerization, the kinetic difference of which in the process of formation of polymer fractions with their characteristic average molecular weights and the most probable MWD, is associated with their difference in the concentrations of pre-reaction catalytic centers and the rate constants of reactions occurring on them. For each type of active centers, partial conversions of monomer consumption and rate constants of initiation, chain propagation, and chain transfer to the monomer are determined.