Synthesis And Micellization Of Biodegradable PBLG-b-PCL-b-PEEP Triblock Compolymer

N-tert-butoxycarbonyl-terminated poly（caprolactone）（Boc-PCL-OH） wassynthesized by ring opening polymerization of ε-caprolactone initiated byN-tert-butoxycarbonyl ethanolamine using stannous octoate as a catalyst.Boc-PCL-OH was used as macroiniator to initiate ring opening polymerization ofethyl ethylene phosphate（EEP） to produce poly（caprolactone）/poly（ethyl ethylenephosphate）（Boc-PCL-b-PEEP）, which was deprotected to give amino terminatedcopolymer（H2N-PCL-b-PEEP）. H2N-PCL-b-PEEP was used as macroiniator toinitiate ring opening polymerization of N-carboxyanhydride of γ-benzyl-L-glutamate（BLG-NCA） to produce poly（γ-benzyl-L-glutamic acid）/poly（caprolactone）/poly（ethyl ethylene phosphate）（PBLG-b-PCL-b-PEEP） triblock compolymer.FT-IR,¹H NMR and GPC were used to confirm the copolymer. Theself-assembly behavior of the compolymer in aqueous solution was studied. Thecritical micelle concentration （CMC） was in a range of4.8×10^-4mg/mL to4.7×10^-3mg/mL. The size of the micelles was in a range of76to113nm, anddecreased with increasing of the proportion of PEEP segments. Polymers aretemperature-sensitive and it become evident with increasing of the proportion ofPEEP segments. The TEM images demonstrate that all micelles are spherical.