Precision synthesis of hybrid block copolymers by organotellurium-mediated successive living radical and cationic polymerizations.

Living cationic polymerization reactions using organotellurium compounds as initiators are reported. Polymerization of vinyl ethers in the presence of an organotellurium initiator and a Lewis acid, such as In(OTf)(3) and BF(3)·OEt(2), affords well-controlled poly(vinyl ether)s with predetermined molecular weights and narrow molecular-weight distributions. Poly(meth)acrylates possessing organotellurium group at the ω-polymer end, which are prepared using organotellurium-mediated controlled/living radical polymerization (TERP), are used as macroinitiators for living cationic polymerization. The one-pot, two-step reaction of the macroinitiator with vinyl ether under radical and cationic conditions gives well-controlled AB diblock copolymers. ABA triblock copolymers with controlled structures are also synthesized from a bifunctional organotellurium initiator.