Use of mono‐ and multifunctional oxocarbenium salts in the polymerization of tetrahydrofuran

Oxocarbenium ions associated to a stable counterion SbF6− were used to initiate the polymerization of tetrahydrofuran; mono‐, di‐, and trifunctional initiators were prepared. They proceed by addition onto the monomer with formation of an ester group and react quantitatively; initiation by the mono‐ and di‐functional salts is rapid. This kind of derivative was used in order to prepare block and graft copolymers of controlled structure.