Living Polymers by the Use of Trithiocarbonates as Reversible Addition−Fragmentation Chain Transfer (RAFT) Agents: ABA Triblock Copolymers by Radical Polymerization in Two Steps

(calcd) is basedon the assumption that all chains contain one trithio-carbonate moiety, it is important to realize that a smallnumber of dead chains are produced by radical-radicaltermination.Polymers prepared with symmetrical trithiocarbon-ates should have the active functionality located in thecenter, e.g.,