Synthesis of Amphiphilic Comb‐Shape Copolymers Via Ring‐Opening Polymerization of a Macromonomer

Amphiphilic comb‐shape copolymers PCL‐ co ‐P(MTC‐mPEG 16 ) (where PCL, MTC, and mPEG refer to poly(ε‐caprolactone), 2‐methyltrimethylene carbonate, and methoxy poly(ethylene glycol), respectively) are synthesized by ring‐opening polymerization of ε ‐caprolactone and cyclic carbonate‐terminated PEG macromonomer (MTC‐mPEG 16 ) with benzyl alcohol as an initiator and Sn(Oct) 2 as a catalyst. Amphiphilic copolymers PCL‐ co ‐P(MTC‐mPEG 16 ) can form micelles in aqueous solution by self‐assembly. The diameters of PCL‐ co ‐P(MTC‐mPEG 16 ) micelles characterized by dynamic light scattering area few dozens of nanometers with a narrow size distribution and the morphology of the micelles observed through transmission electron microscopy are nanosized spheres. The in vitro drug release of comb‐shape copolymer PCL‐ co ‐P(MTC‐mPEG 16 ) micelles is more stable and sustained than that of linear block copolymers mPEG‐ b ‐PCL.