POLYMERIZATION OF CARBAZOLYL-CONTAINING EPOXIDES WITH TRIPHENYLCARBENIUM SALTS

Polymerization of 9-(2,3-epoxypropyl)carbazole (EPC) and 1,2-epoxy-6-( 9-carbazolyl)-4-oxahexane (ECOH) with triphenylearbenium hexachloroant imonate and triphenylcarbenium tetrafluoroborate have been studied by the microoalorimetric technique. Triphenylcarbenium salts have turn ou t to be more efficient catalyst for the polymerization of carbazolyl-c ontaining epoxides than Lewis acids, giving high yields at low initial concentration of the catalyst. Using comparatively restricted conditi ons 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 th e conventional active chain end mechanism to the activated monomer mec hanism has been observed at a sufficiently high degree of conversion o fmonomer.