Polymer Bulletin

, Volume 15, Issue 4, pp 317–323

Living carbocationic polymerization

III. Demonstration of the living polymerization of isobutylene
  • R. Faust
  • J. P. Kennedy

DOI: 10.1007/BF00254850

Cite this article as:
Faust, R. & Kennedy, J.P. Polymer Bulletin (1986) 15: 317. doi:10.1007/BF00254850


A new family of initiating systems has been discovered that efficiently induces the truly living polymerization of isobutylene (IB). The initiating systems are complexes of organic tertiary esters e.g., cumyl acetate, 2,4,4-trimethylpentane-2-acetate, with BCl3. Living polymerizations proceed very rapidly in a variety of solvents, i.e., CH3Cl, CH2Cl2, C2H5Cl, and mixtures of chlorinated solvents plus n-hexane, in the range from −10° to −50°C. The living nature of the polymerizations was demonstrated by linear ¯Mn versus WPIB (g of polymer formed) plots starting at the origin and horizontal N (number of PIB chains) versus WPIB plots. The DPn of the products obeys [Mo]/[Io] where [Mo] and [Io] are initial monomer and initiator concentrations, respectively. Conversions and initiator efficiencies are ∼100%. In carefully controlled experiments narrow molecular weight distribution polyisobutylenes (PIB) have been obtained, i.e., Mw/Mn=1.17 − 1.3. A mechanism is outlined that helps rationalize the findings. It is postulated that the living polymerization of IB initiated by organic tertiary ester·BCl3 complexes most likely proceeds by a two-component group transfer polymerization process.

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • R. Faust
    • 1
  • J. P. Kennedy
    • 1
  1. 1.Institute of Polymer ScienceUniversity of AkronAkronUSA