| 초록 |
One-pot synthesis of thermosensitive, amphiphilic poly(ε-caprolactone)-b-poly(N-vinylcaprolactam) (PCL-b-PVCL) block copolymers was performed at 30 °C a hydroxyl-functionalized RAFT agent, 2-hydroxyethyl 2-(ethoxycarbonothioylthio) propanoate, as a dual initiator for RAFT polymerization and ROP. Hydrophobic PCL blocks were first synthesized via the ROP of ε-caprolactone (CL) using diphenyl phosphate as a catalyst followed by the RAFT polymerization of N-vinylcaprolactam (VCL) by the addition of VCL and 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V-70) to the reaction mixture. VCL quenched the ROP of CL, and V-70 initiated the RAFT polymerization of VCL. The PCL-b-PVCL micelles exhibited repetitive aggregation and dispersion during reversible cooling and heating cycles between 20 and 40 °C due to the thermosensitive behavior of the PVCL shell. |
