Synthesis and characterization of triblock copolymers of poly(γ-benzyl L-glutamate)-b-poly(tetrahydrofuran)-b-poly(γ-benzyl L-glutamate)

A kind of novel biodegradable triblock copolymers of poly (γ-benzyl L-glutamate)-b-poly (tetrahydrofuran)-b-poly(γ-benzyl L-glutamate) was synthesized by using amino-terminated poly(tetrahydrofuran) as a macroinitiator to initiate the anionic ring-opening polymerization of γ-benzyl L-glutamate N-carboxyanhydride (BLG-NCA) made from the reaction of γ-benzyl L-glutamate with triphosgen in tetrahydrofuran. The molecular structure was characterized by IR, ¹H-NMR, DSC and GPC measurements. The results showed that the triblock copolymers are well tailored by varying the feeding molar ratio of monomer to macroinitiator below 100. DSC analysis indicated that no crystalline phase is found in the copolymers and the glass transition temperature of each block gets close gradually with the block length of poly(γ-benzyl L-glutamate) growing. These triblock polymers could act as potential candidates for drug delivery carriers and tissue-engineered scaffolds.