Synthesis and characterization of biodegradable poly(ε-caprolactone)/poly(γ-benzyl l -glutamate) block copolymer

A biodegradable poly(ε-caprolactone)/poly(γ-benzyl l -glutamate) (PCL- b -PBLG) block copolymer was synthesized by ring-opening polymerization of N -carboxy-γ-benzyl l -glutamate anhydride (BLG-NCA) with amine-terminated poly(ε-caprolactone) (PCL-NH 2 ) as a macroinitiator. The PCL-NH 2 was prepared by deprotection of a PCL-CH 2 CH 2 NHBoc, which was obtained by ring-opening polymerization of ε-caprolactone (ε-CL) initiated by Boc-aminoethanol (HOCH 2 CH 2 NHBoc) using stannous octanoate as catalyst under microwave irradiation. The structures of the block copolymers were determined by IR, 1 H NMR, and GPC measurements. The results prove that BLG-NCA can be initiated by PCL-NH 2 to produce PCL- b -PBLG block copolymers.