Synthesis functional poly(carbonate-b-ester) copolymers and micellar characterizations

Functional poly(carbonate-b-ester)s were synthesized in buck by ring-opening polymerization of the carbonate (TMC, MBC, or BMC) with ferf-butyl N-(2-hydroxyethyl) carbamate as an initiator, and then with ε-CL (or ε-BCL) comonomer. Subsequently, the PMMC-b-PCL with pendent carboxyl groups and the PTMC-b-PHCL with pendent hydroxyl groups were obtained by catalytic debenzylation. DSC analysis indicated that only one T_g at an intermediate temperature the T_gS of the two polymer blocks. A decrease T_g was observed when an increase contents of ε-CL incorporated into the copolymers. In contrast, two increased T_ms were observed with increasing PCL content. The block copolymers formed micelle in aqueous phase with critical micelle concentrations (cmcs) in the range of 2.23-14.6 mg/L and with the mean hydrodynamic diameters in the range of 100-280 nm, depending on the composition of copolymers. The drug entrapment efficiency and hydrolytic degradation behavior of micelle were also evaluated.