Catholic polymerization of dl-lactide

Abstract A study was made of cationic polymerization of dl -lactide in melt with and SnCl 2 ·2H 2 O initiators. Up to 70–80% conversion the process is independent of the concentration of components and is described by the empirical equation − d [M]/ dt = k eff , where k eff is the effective rate constant of polymerization. Process kinetics are explained within the framework of ideas about the mechanism of cationic polymerization of lactones considering the predominance of monomer basicity over polymer basicity and the presence in the system of ionic associates of triplet type. MW data confirm chain transfer in both processes.