Amphiphilic ABA triblock copolymers via combination of ROMP and ATRP in ionic liquid: Synthesis, characterization, and self-assembly

A new amphiphilic ABA triblock copolymer was synthesized by ring-opening metathesis polymerization (ROMP) and atom transfer radical polymerization (ATRP) in ionic liquid (IL). The bromo-terminated macroinitiator was prepared via ROMP of norbornene derivative, which is compatible with ionic liquid [bmim][BF4], in conjunction with a chain transfer agent (CTA) in [bmim][BF4]. ROMP with CTA in [bmim][BF4] exhibited a different performance by changing the reaction conditions, and importantly there has been a good control over polymerization process and relatively low polydispersity index of polymer in [bmim][BF4]. Based on the telechelic macroinitiator, the amphiphilic ABA triblock copolymer was synthesized by ATRP in [bmim][BF4]. The prepared PDMAEMA-PNBEDE-PDMAEMA triblock copolymer can self-assemble spontaneously in H2O to form polymeric micelles, which was characterized by DLS, AFM, and TEM.