Theoretical study of chain transfer in anionic polymerization. Transfer by the mechanism of side-group substitution

• Published in: Macromolecular theory and simulations 1992-09, Vol.1 (5), p.321-331
• Main Authors: Litvinenko, Galina I., Arest-Yakubovich, Alexander A.
• Format: Article
• Language: English
• ISSN: 1022-1344; 1521-3919
• DOI: 10.1002/mats.1992.040010506

A new theoretical consideration of chain transfer to monomer in the anionic polymerization of hydrocarbon monomers is presented. It is shown that the kinetic scheme used in theoretical studies reported previously contradicts the widespread views on the chemical mechanism of carbanionic reactions. It is suggested that the most probable path of the transfer reaction is the proton ion from the side group of the monomer; the terminal double bond of the monomer molecule remains unchanged, and therefore the intermediate species can participate in succeeding reactions as a macromonomer. The molecular characteristics of polymer formed in processes with monomer transfer by side‐group substitution are determined. At high conversion, the polymer formed in such a process is shown to possess a number‐average degree of polymerization, P̄n, approaching the theoretical value for living polymers, and a P̄w exceeding it the more the higher the intensity of transfer. Furthermore, it shows a broad molecular weight distribution and a fairly noticeable degree of branching. These results considerably differ from those previously reported.