KINETICS OF PI-CROTYLNICKEL IODIDE CATALYZED BUTADIENE POLYMERIZATION

The polymerization of 1,3-butadiene by π-crotylnickel iodide was studied in a constant-pressure system under pseudo-zero-order reaction conditions. The rate law is given in the Results. In the initial stages of polymerization the molecular weight of the polymer increased with conversion and the dispersion of molecular weight was very narrow. With increasing conversion the number of polymer molecules per catalyst molecule increased, as did the polydispersity of the polymer. A polymerization mechanism involving rapid initiation by a monomeric allylnickel iodide, slow propagation, and a slow transfer process (probably hydride transfer) is proposed. © 1969, American Chemical Society. All rights reserved.