Living Carbocationic Polymerization. VII. Living Polymerization of Isobutylene by Tertiary Alkyl (or Aryl) Methyl Ether/Boron Trichloride Complexes

Abstract

It has been discovered that the living polymerization of isobutylene (IB) can be induced by MeORt/BCl₃ initiating systems in CH₂C1₂or CH₃C1 at −10 and −30°C. Diagnostic proof for the living polymerizations are 1) proportionality of M _n to polyisobutylene (PIB) formed and 2) independence of number of PIB chains of amount of PIB formed. By the use of agedC(CH₃)₃CH₂OMe/BCl₃ and C₆H₅C(CH₃)₂OMe/BCl₃ systems, initiation efficiency (leff) ≍ 100% and M _n is determined by the [monomer]₀/[initiator]₀ ratio. Polymerizations quenched by methanol yielded f-chloro end groups.