One-step synthesis of poly(methacrylate)-b-polyester via “one organocatalyst, two polymerizations”

By using triarylsulfonium hexafluorophosphate salt as an organocatalyst for both photo-controlled atom transfer radical polymerization (photo-ATRP) and ring-opening polymerization (ROP) at ambient temperature, a well-defined poly(methyl methacrylate)-b-poly(trimethylene carbonate) block copolymer was successfully synthesized in one-step. Notably, the conversions of the two polymerizations in one-pot were both higher than those when polymerized separately (77%, 51% vs. 41%, 20%) which indicated that two polymerizations could promote each other. These two completely different controllable/living polymerizations could take place on one polymer chain at the same time via a “one-pot, one-step” method. Moreover, other methacrylates and cyclic esters were introduced into the system and block copolymers with precise molecular weights and a narrow polydispersity index were successfully synthesized. In the “one organocatalyst, two polymerizations” system, the triarylsulfonium hexafluorophosphate salt could spontaneously catalyze photo-ATRP and ROP. This method is efficient and attractive for preparing complex block copolymers.