Synthesis and Self-Assembly Behavior of AmphiphilicPolypeptide-Based Brush-Coil Block Copolymers

摘要

Synthesis and self-assembly behavior of a novel amphiphilic brush-coilblock copolymer bearing hydrophilic poly(ethylene glycol) segment and hydrophobicpolypeptide brush segment were presented in this work. The poly(y-benzyl-L-gluta-mate) (PBLG) brush is synthesized through "grafting from" strategy by ring-openingpolymerization of γ-benzyl-L-glutamate-N-carboxyanhydride (BLG-NCA) initiated bythe flanking terminal primary amino group of macroinitiator. The copolymers werecharacterized by ~1HNMR, gel permeation chromatography, Fourier transform infra-red, circular dichroism spectrum, and differential scanning calorimetry. The self-assembly behavior of the brush-coil block copolymers in aqueous solution was investi-gated by means of transmission electron microscopy, scanning electron microscopy,atomic force microscopy, and laser light scattering. Spherical micelles were observedwhen the length of PBLG brush is shorter. The aggregate morphology transforms tospindle-like micelles and then to rod-like micelles, as the length of polypeptide brush increases.