Polymerization of carbazolyl-containing epoxides with triphenylcarbenium salts

Abstract

Polymerization of 9-(2,3-epoxypropyl)carbazole (EPC) and 1,2-epoxy-6-(9-carbazolyl)-4-oxahexane (ECOH) with triphenylearbenium hexachloroantimonate and triphenylcarbenium tetrafluoroborate have been studied by the microoalorimetric technique. Triphenylcarbenium salts have turn out to be more efficient catalyst for the polymerization of carbazolyl-containing epoxides than Lewis acids, giving high yields at low initial concentration of the catalyst. Using comparatively restricted conditions of reaction ([triphenylcarbenium salt]o greater-than-or-equal-to 0.02 mol/l, t greater-than-or-equal-to 50-degrees-C) transition from the conventional active chain end mechanism to the activated monomer mechanism has been observed at a sufficiently high degree of conversion ofmonomer.