Poly(ethylene glycol)-b-poly(5-benzyloxy-trimethylene carbonate-lactic acid) copolymers (PEG-b-P(BTMC-LA)) were synthe-
sized by ring-opening polymerization of lactide and 5-benzyloxy trimethylene carbonate in the presence of mono-hydroxyl poly(eth-
ylene glycol) with diethyl zinc as catalyst. They were further converted into deprotected copolymers with the pendant hydroxyl
groups by hydrogenolysis in the presence of Pd(OH)
2
/C, and ?nally conjugated with biotin through the free hydroxyl groups.
Gel permeation chromatography, Fourier transform infrared, di?erential scanning calorimetry and
1
H nuclear magnetic resonance
studies con?rmed the copolymer structures and successful attachment of biotin to the copolymer.
